NM: Individual County Chronologies

John H. Long, Editor; Peggy Tuck Sinko, Associate Editor; Emily Kelley, Historical Compiler; Laura Rico-Beck, GIS Specialist and Digital Compiler; Peter Siczewicz, ArcIMS Interactive Map Designer; Robert Will, Cartographic Assistant

ARIZONA (extinct) created by New Mexico Territory from DOÑA ANA. ARIZONA (extinct) was located entirely within present Arizona. (N.M. Terr. Laws 1859-1860, 9th assy. /p. 74)

ARIZONA (extinct) eliminated when it lost all territory to DOÑA ANA. (N.M. Terr. Laws 1861-1862, 11th assy. /p. 18)

ARIZONA (extinct) re-created from DOÑA ANA. (N.M. Terr. Laws 1862-1863, 12th assy. /p.30)

ARIZONA (extinct) eliminated when the United States created Arizona Territory from New Mexico Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

BERNALILLO established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between BERNALILLO and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

BERNALILLO recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

BERNALILLO gained from VALENCIA and Non-County Area 1, exchanged with SAN MIGUEL, and lost to SANTA ANA and SANTA FE when all counties redefined; included parts of present Arizona, Nevada and New Mexico. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 292)

BERNALILLO lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

BERNALILLO had lost to SAN MIGUEL. Though no law has been found authorizing this change, the definition for the creation of LINCOLN on 16 January 1869 depends on the SAN MIGUEL boundary having been extended southward as mapped. (Coan, 259)

BERNALILLO lost to VALENCIA. (N.M. Terr. Laws 1869-1870, 19th assy., ch. 16/p. 44)

BERNALILLO gained all of SANTA ANA (extinct); SANTA ANA eliminated. (N.M. Terr. Laws 1875-1876, 22d assy., ch. 8/pp. 38-40)

BERNALILLO exchanged with SANTA FE. BERNALILLO was divided into two parts encompassing territory east and west of SANTA FE. (N.M. Terr. Laws 1882, 25th assy., ch. 83/p. 174)

BERNALILLO exchanged with SANTA FE. (N.M. Terr. Laws 1888, 28th assy., ch. 127/pp. 301-302)

BERNALILLO gained from SANTA FE. (N.M. Terr. Laws 1891, 29th assy., ch. 55/pp. 106-107)

BERNALILLO gained from RIO ARRIBA. (N.M. Terr. Laws 1895, 31st assy., ch. 10/pp. 41-42)

BERNALILLO lost to GUADALUPE (original). (N.M. Terr. Laws 1897, 32d assy., ch. 8/p. 22)

BERNALILLO lost to creation of McKINLEY, and lost to VALENCIA. Act passed 23 February 1899; took effect 1 January 1901. (N.M. Terr. Laws 1899, 33d assy., ch. 19/pp. 43-45)

BERNALILLO lost to McKINLEY and VALENCIA. (N.M. Terr. Laws 1901, 34th assy., ch. 39/pp. 75-79)

BERNALILLO lost to creation of SANDOVAL. Act passed 10 March 1903; took effect 14 April 1903. (N.M. Terr. Laws 1903, 35th assy., ch. 27/pp. 37-43)

BERNALILLO lost to creation of TORRANCE. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

Legislature authorized the creation of SOUTH VALLEY (proposed) from BERNALILLO, dependent on a vote in the general election of 5 November 1996. Proposal failed in referendum [no change]. (N.M. Laws 1995, 42d reg. sess., ch. 85/pp. 726-736; N.M. Stat. 1978 Annotated, 2001 Cumulative Supplement, ch. 4, pamphlet 11, article 1A, p. 1)

Cape Girardeau District (now CAPE GIRARDEAU, Mo.) gained from New Madrid District (now NEW MADRID, Mo.); included part of the northeast corner of present New Mexico. (Ford, 5-6)

Cape Girardeau District (now CAPE GIRARDEAU, Mo.) lost to creation of non-county area in Missouri Territory when its western line was redefined as the boundary of the "Osage Purchase". Cape Girardeau eliminated from New Mexico. (Royce, 676-677, pls. 112, 144; Terr. Papers U.S., 14:599-601)

An unofficial convention held in Tucson (Ariz.) established a provisional government, declared the creation of the Territory of Arizona from all that part of New Mexico Territory that lay south of 33 degrees 40 minutes north latitude, and authorized the creation of CASTLE DOME (Ariz., proposed). Congress failed to recognize the new territory and its proposed counties [no change]. (Sacks, 36, 151; Swindler, 1:244-248)

CATRON created from SOCORRO. (N.M. Laws 1921, 5th reg. sess., ch. 28/pp. 37-45)

Legislature authorized the elimination of CATRON by the creation of RIO GRANDE (proposed) and the expansion of GRANT. This act attempted to circumvent the constitutional prohibition against changing county boundaries by special or local law and the attorney general filed action to prevent implementation of the statute. Proposal failed on 3 April 1928 when the New Mexico Supreme Court ruled the act unconstitutional [no change]. (N.M. Laws 1927, 8th reg. sess., chs. 185-186/pp. 457-464; N.M. Constitution 1910, art. IV, sec. 2, in Swindler, 7:102-103; "State ex rel. Dow v. Graham," in N.M. Reports, 33:504-519; N.M. Stat. 1978, ch. 4, pamphlet 11, 4-28-1 "Socorro County Laws" 1927, ch. 185; Coan reprint, 20)

CHAVES created by New Mexico Territory from LINCOLN. EDDY attached to CHAVES "for judicial purposes." Act passed 25 February 1889; took effect 1 January 1891. (N.M. Terr. Laws 1888, 28th assy., ch. 87/pp. 202-207)

EDDY fully organized; detached from CHAVES. (N.M. Terr. Laws 1891, 29th assy., ch. 19/p. 38)

CHAVES gained from LINCOLN. (N.M. Terr. Laws 1899, 33d assy., ch. 3/pp. 21-30)

CHAVES lost to creation of ROOSEVELT. (N.M. Terr. Laws 1903, 35th assy., ch. 7/pp. 12-16)

CHAVES lost to creation of DE BACA and LEA, and lost to ROOSEVELT. (N.M. Laws 1917, 3rd reg. sess., chs. 11, 23/pp. 41-48, 108-110)

CIBOLA created from VALENCIA. (N.M. Laws 1981, 35th reg. sess., ch. 24/pp. 76-80)

COLFAX created by New Mexico Territory from MORA. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 24/pp. 57-62)

COLFAX gained from MORA. (N.M. Terr. Laws 1875-1876, 22d assy., ch. 61/p. 162)

COLFAX attached to TAOS "for judicial purposes" [law repealed 24 January 1878]. (N.M. Terr. Laws 1875-1876, 22d assy., ch.6/pp. 35-37)

COLFAX detached from TAOS when the law of 14 January 1876 was repealed. (N.M. Terr. Laws 1878, 23d assy., ch. 9/p. 60)

COLFAX lost to MORA. (N.M. Terr. Laws 1882, 25th assy., ch. 72/pp. 158-159)

COLFAX lost to creation of UNION. Act passed 23 February 1893; took effect 1 January 1894. (N.M. Terr. Laws 1893, 30th assy., ch. 49/pp. 68-75)

CURRY created by New Mexico Territory from QUAY and ROOSEVELT. (N.M. Terr. Laws 1909, 38th assy., ch. 6/pp. 9-13)

DE BACA created from CHAVES, GUADALUPE, and ROOSEVELT. (N.M. Laws 1917, 3rd reg. sess., ch. 11/pp. 41-48)

Faulty geographic information on the Disturnell map referenced in the Treaty of Guadalupe-Hidalgo led to a dispute between the United States and Mexico over the exact location and extent of the international boundary. The dispute was settled on 30 December 1853 when the Gadsden Purchase established the international boundary at its present location. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452; Baldwin, 117-137; Van Zandt, 28-29, 162-165)

DOÑA ANA created by New Mexico Territory from Non-County Area 1; included parts of present Arizona and New Mexico, and the disputed area with Mexico. DOÑA ANA first mentioned in a 10 July 1851 law establishing judicial districts, and on 06 January 1852 the legislature authorized its creation from SOCORRO, however, no complete boundary definition is given for either county until 09 January 1852. (N.M. Terr. Laws 1851, 1st assy., 1st sess./p. 119; N.M. Terr. Laws 1851, 1st assy., 2d sess. /pp. 266, 292)

DOÑA ANA gained all of Non-County Area 2. (N.M. Terr. Laws 1854, 4th assy. /p. 57)

DOÑA ANA lost to creation of ARIZONA (extinct). (N.M. Terr. Laws 1859-1860, 9th assy. /p. 74)

DOÑA ANA gained all of ARIZONA (extinct) when the law creating ARIZONA was repealed. (N.M. Terr. Laws 1861-1862, 11th assy. /p. 18)

DOÑA ANA lost to re-creation of ARIZONA (extinct). (N.M. Terr. Laws 1862-1863, 12th assy. /p.30)

DOÑA ANA lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

DOÑA ANA lost to SOCORRO. (N.M. Terr. Laws 1866-1867, 16th assy. /p. 104)

DOÑA ANA lost to creation of GRANT. (N.M. Terr. Laws 1867-1868, 17th assy., ch. 20/p. 88)

DOÑA ANA gained from SOCORRO. (N.M. Terr. Laws 1869-1870, 19th assy., ch. 11/p. 36)

DOÑA ANA lost to SOCORRO. (N.M. Terr. Laws 1871-1872, 20th assy., ch. 2/pp. 4-5)

DOÑA ANA lost to LINCOLN. (N.M. Terr. Laws 1878, 23d assy., ch. 34/pp. 82-83)

DOÑA ANA lost to SOCORRO. (N.M. Terr. Laws 1880, 24th assy., ch. 42/pp. 98-99)

DOÑA ANA gained from GRANT. (N.M. Terr. Laws 1880, 24th assy., ch. 43/p. 99)

DOÑA ANA lost to creation of SIERRA. (N.M. Terr. Laws 1884, 26th assy., ch. 109/pp. 223-225)

DOÑA ANA gained from LINCOLN and SOCORRO. (N.M. Terr. Laws 1887, 27th assy., ch. 14/p. 39)

DOÑA ANA lost to LINCOLN. (N.M. Terr. Laws 1888, 28th assy., ch. 41/pp. 92-93)

DOÑA ANA lost to creation of OTERO. (N.M. Terr. Laws 1899, 33d assy., ch. 3/pp. 21-30)

DOÑA ANA lost to creation of LUNA. (N.M. Terr. Laws 1901, 34th assy., ch. 38/pp. 70-75)

An unofficial convention held in Tucson (Ariz.) established a provisional government, declared the creation of the Territory of Arizona from all that part of New Mexico Territory that lay south of 33 degrees 40 minutes north latitude, and authorized the creation of DOÑA ANA (Ariz., proposed). Congress failed to recognize the new territory and its proposed counties [no change]. (Sacks, 36, 151; Swindler, 1:244-248)

EDDY created by New Mexico Territory from LINCOLN. EDDY not fully organized, attached to CHAVES "for judicial purposes." Act passed 25 February 1889; took effect 1 January 1891. (N.M. Terr. Laws 1888, 28th assy., ch. 87/pp. 202-207)

EDDY fully organized; detached from CHAVES. (N.M. Terr. Laws 1891, 29th assy., ch. 19/p. 38)

EDDY gained from LINCOLN. (N.M. Terr. Laws 1895, 31st assy., ch. 11/p. 42)

EDDY lost to creation of LEA. (N.M. Laws 1917, 3rd reg. sess., ch. 23/pp. 108-110)

An unofficial convention held in Tucson (Ariz.) established a provisional government, declared the creation of the Territory of Arizona from all that part of New Mexico Territory that lay south of 33 degrees 40 minutes north latitude, and authorized the creation of EWELL (Ariz., proposed). Congress failed to recognize the new territory and its proposed counties [no change]. (Sacks, 36, 151; Swindler, 1:244-248)

Gadsden Purchase settled the boundary dispute between the United States and Mexico and established the international line at its present location. (U.S. Stat., vol. 10, pp. 1031-1037; Van Zandt, 11, 29, 162)

Area acquired in the Gadsden Purchase became Non-County Area 2 when it was officially added to New Mexico Territory without being assigned to a county. (U.S. Stat., vol. 10, ch. 245[1854]/p. 575; Van Zandt, 162; Walker and Bufkin, 21-22)

GRANT created by New Mexico Territory from DOÑA ANA and SOCORRO. (N.M. Terr. Laws 1867-1868, 17th assy., ch. 20/p. 88)

GRANT lost to DOÑA ANA. (N.M. Terr. Laws 1880, 24th assy., ch. 43/p. 99)

GRANT lost to creation of SIERRA (N.M. Terr. Laws 1884, 26th assy., ch. 109/pp. 223-225)

GRANT lost to creation of LUNA. (N.M. Terr. Laws 1901, 34th assy., ch. 38/pp. 70-75)

GRANT boundaries with SOCORRO and SIERRA were redefined to run on the line between Township 12S and Township 13S [no mappable change]. (N.M. Laws 1917, 3rd reg. sess., ch. 57/pp. 178-179)

GRANT lost to creation of HIDALGO. (N.M. Laws 1919, 4th reg. sess., ch. 11/pp. 11-12)

Legislature authorized GRANT to gain from CATRON. This act attempted to circumvent the constitutional prohibition against changing county boundaries by special or local law and the attorney general filed action to prevent implementation of the statute. Proposal failed on 3 April 1928 when the New Mexico Supreme Court ruled the act unconstitutional [no change]. (N.M. Laws 1927, 8th reg. sess., chs. 185-186/pp. 457-464; N.M. Constitution 1910, art. IV, sec. 2, in Swindler, 7:102-103; "State ex rel. Dow v. Graham," in N.M. Reports, 33:504-519; N.M. Stat. 1978, ch. 4, pamphlet 11, 4-28-1 "Socorro County Laws" 1927, ch. 185; Coan reprint, 20)

GUADALUPE (original) created by New Mexico Territory from SAN MIGUEL. Act passed 26 February 1891, became effective 1 January 1893. (N.M. Terr. Laws 1891, 29th assy., ch. 88/pp. 175-180)

GUADALUPE (original) gained from BERNALILLO. (N.M. Terr. Laws 1897, 32d assy., ch. 8/p. 22)

GUADALUPE (original) lost to creation of QUAY and ROOSEVELT. (N.M. Terr. Laws 1903, 35th assy., chs. 7-8/pp. 12-20)

GUADALUPE (original) eliminated by creation of LEONARD WOOD (now GUADALUPE) and Non-County Area 3. (N.M. Terr. Laws 1903, 35th assy., ch. 69/pp. 127-131)

LEONARD WOOD (now GUADALUPE) created by New Mexico Territory from VALENCIA and GUADALUPE (original), which was eliminated. (N.M. Terr. Laws 1903, 35th assy., ch. 69/pp. 127-131)

LEONARD WOOD renamed GUADALUPE. (N.M. Terr. Laws 1905, 36th assy., ch. 20/p. 57)

GUADALUPE lost to creation of DE BACA. (N.M. Laws 1917, 3rd reg. sess., ch. 11/pp. 41-48)

HARDING created from MORA and UNION. (N.M. Laws 1921, 5th reg. sess., ch. 48/pp. 106-107)

HARDING lost to creation of JEFFERSON (now SAN MIGUEL). (N.M. Laws 1923, 6th reg. sess., ch. 142/pp. 281-283)

HIDALGO created from GRANT. (N.M. Laws 1919, 4th reg. sess., ch. 11/pp. 11-12)

LEA created from CHAVES and EDDY. (N.M. Laws 1917, 3rd reg. sess., ch. 23/pp. 108-110)

LINCOLN created by New Mexico Territory from SOCORRO. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 8/pp. 28-31)

LINCOLN gained from DOÑA ANA. (N.M. Terr. Laws 1878, 23d assy., ch. 34/pp. 82-83)

LINCOLN lost to DOÑA ANA. (N.M. Terr. Laws 1887, 27th assy., ch. 14/p. 39)

LINCOLN gained from DOÑA ANA. (N.M. Terr. Laws 1888, 28th assy., ch. 41/pp. 92-93)

LINCOLN lost to creation of CHAVES and EDDY. Act passed 25 February 1889; took effect 1 January 1891. (N.M. Terr. Laws 1888, 28th assy., ch. 87/pp. 202-207)

LINCOLN lost to VALENCIA. LINCOLN boundary with SOCORRO redefined to run along the public land survey line between ranges 8E and 9E [no mappable change]. (N.M. Terr. Laws 1893, 30th assy., ch. 20/pp. 36-37)

LINCOLN lost to EDDY. (N.M. Terr. Laws 1895, 31st assy., ch. 11/p. 42)

LINCOLN lost to creation of OTERO, and lost to CHAVES. (N.M. Terr. Laws 1899, 33d assy., ch. 3/pp. 21-30)

LINCOLN lost to creation of TORRANCE. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

LINCOLN exchanged with SOCORRO. (N.M. Terr. Laws 1909, 38th assy., ch. 112/pp. 326-327)

LOS ALAMOS created from SANDOVAL and SANTA FE. (N.M. Laws 1949, 19th reg. sess., ch. 134/pp. 319-321)

LUNA created by New Mexico Territory from DOÑA ANA and GRANT. (N.M. Terr. Laws 1901, 34th assy., ch. 38/pp. 70-75)

McKINLEY created by New Mexico Territory from BERNALILLO. Act passed 23 February 1899; took effect 1 January 1901. (N.M. Terr. Laws 1899, 33d assy., ch. 19/pp. 43-45)

McKINLEY gained from BERNALILLO, SAN JUAN, and VALENCIA. (N.M. Terr. Laws 1901, 34th assy., ch. 39/pp. 75-79)

An unofficial convention held in Tucson (Ariz.) established a provisional government, declared the creation of the Territory of Arizona from all that part of New Mexico Territory that lay south of 33 degrees 40 minutes north latitude, and authorized the creation of MESILLA (Ariz., proposed). Congress failed to recognize the new territory and its proposed counties [no change]. (Sacks, 36, 151; Swindler, 1:244-248)

All of present New Mexico came under Spanish control when the Adams-Onis Treaty between the United States and Spain established the boundary between the two countries from the Gulf of Mexico to the Pacific Ocean. Ratifications exchanged 22 February 1821. (Parry, 70:1-30; Van Zandt, 26-27)

Mexico gained its independence from Spain; present New Mexico became part of the Republic of Mexico. (Beers, 100; "Mexican War of Independence," New Handbook of Texas, 4:698)

New Mexico was declared a territory of the Republic of Mexico; included western part of present Texas. (Stribling, 16; Weber, 23-25)

Treaty of Limits between Mexico and the United States defined the boundary between the two countries to be the same as established by the 1819 Adams-Onis Treaty with Spain. (Parry, 78:35-42; Van Zandt, 121)

New Mexico became a Department in the Republic of Mexico when the new Constitution became law. (Bloom, 3-18)

The U.S. Army of the West, under command of Brigadier General Stephen Watts Kearny, took control of Santa Fe and proclaimed United States sovereignty over the territory of New Mexico (Mexico). (Williams 108-110)

Treaty of Guadalupe-Hidalgo ended the war between Mexico and the United States. Area ceded by Mexico became Unorganized Federal Territory (non-county area) in the United States; included all of present California, Nevada, and Utah, and parts of present Arizona, Colorado, New Mexico, and Wyoming. Part of the international boundary was in dispute (see 13 December 1850). Mexico retained parts of present Arizona and New Mexico; only the portion in New Mexico is mapped. (U.S. Stat., vol. 9, pp. 922-943; Parry, 102: 29-59; Van Zandt, 11, 28-29; Walker and Bufkin, 19, 20A)

The parts of present Arizona and New Mexico located south of the boundary defined in the Treaty of Guadalupe-Hidalgo were part of Mexico. Faulty geographic information on the Disturnell map referenced in the treaty led to a dispute between the United States and Mexico over the exact location and extent of the international boundary. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452; Baldwin, 117-137; Van Zandt, 28-29, 162-165)

Non-county area in Missouri Territory created from CAPE GIRARDEAU (Mo.), NEW MADRID (Mo.), ST. LOUIS (Mo.), and STE. GENEVIEVE (Mo.), when their western boundaries were redefined as the boundary of the "Osage Purchase". Non-county are overlapped the northeast corner of present New Mexico; only the area of overlap is mapped. (Royce, 676-677, pls. 112, 144; Terr. Papers U.S., 14:599-601)

Non-county area in Missouri Territory lost to creation of ARKANSAS (Ark.); portion of non-county area that overlapped present New Mexico unchanged. (Mo. Terr. Laws 1813-1814, ch. 99, sec. 1/pp. 293-295)

Non-county area in Missouri Territory lost to Spain when the Adams-Onis Treaty between the United States and Spain established the boundary between the two countries from the Gulf of Mexico to the Pacific Ocean. Ratifications exchanged 22 February 1821. All of present New Mexico became part of Spain. (Parry, 70:1-30; Van Zandt, 26-27)

MORA created by New Mexico Territory from TAOS; included parts of present Colorado and New Mexico. (N.M. Terr. Laws 1859-1860, 9th assy. /p. 76)

MORA lost to creation of Colorado Territory. (U.S. Stat., vol. 12, pp. 172-177; Van Zandt, 141-144)

Boundary between MORA and TAOS redefined [no change]. (N.M. Terr. Laws 1867-1868, 17th assy., ch. 24/p. 106)

MORA lost to creation of COLFAX. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 24/pp. 57-62)

MORA lost to COLFAX. (N.M. Terr. Laws 1875-1876, 22d assy., ch. 61/p. 162)

MORA gained from SAN MIGUEL. (N.M. Terr. Laws 1882, 25th assy., ch. 86/pp. 176-177)

MORA gained from COLFAX. (N.M. Terr. Laws 1882, 25th assy., ch. 72/pp. 158-159)

MORA lost to SANTA FE. (N.M. Terr. Laws 1882, 25th assy., ch. 83/p. 174)

Boundary between MORA and SAN MIGUEL redefined [no change]. (N.M. Terr. Laws 1888, 28th assy., ch. 37/p. 89)

MORA gained from SANTA FE. (N.M. Terr. Laws 1888, 28th assy., ch. 127/pp. 301-302)

MORA lost to creation of UNION. Act passed 23 February 1893; took effect 1 January 1894. (N.M. Terr. Laws 1893, 30th assy., ch. 49/pp. 68-75)

MORA lost to creation of HARDING. (N.M. Laws 1921, 5th reg. sess., ch. 48/pp. 106-107)

New Madrid District (now NEW MADRID, Mo.) created within the District of Louisiana (Mo.); included the northeast corner of present New Mexico. (Terr. Papers U.S., 13: 51-52; U.S. Stat., vol. 2, ch. 38 [1804]/pp. 283-289; Violette, 46-47)

New Madrid District (now NEW MADRID, Mo.) gained from Cape Girardeau District (now CAPE GIRARDEAU, Mo.); portion of New Madrid in present New Mexico unchanged. (Terr. Papers U.S., 13:541-542; Gov. Proc. 7 June 1806)

New Madrid District (now NEW MADRID, Mo.) lost to Cape Girardeau District (now CAPE GIRARDEAU, Mo.); continued to include part of the northeast corner of present New Mexico. (Ford, 5-6)

New Madrid District (now NEW MADRID, Mo.) lost to creation of non-county area in Missouri Territory when its western line was redefined as the boundary of the "Osage Purchase". New Madrid eliminated from New Mexico. (Royce, 676-677, pls. 112, 144; Terr. Papers U.S., 14:599-601)

The United States created New Mexico Territory from Unorganized Federal Territory and from land purchased from the state of Texas. All that portion of New Mexico Territory lying outside the boundaries of the seven original counties established under Kearny's Code became Non-County Area 1; included most of present Arizona and New Mexico, and parts of present Colorado and Nevada. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452; Baldwin, 117-137; Van Zandt, 28-29, 162-165)

Non-County Area 1 lost to creation of DOÑA ANA and SOCORRO, and lost to BERNALILLO, RIO ARRIBA, SAN MIGUEL, SANTA ANA, TAOS, and VALENCIA; Non-County Area 1 eliminated. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

Non-County Area 2 created when the territory acquired by the United States in the Gadsden Purchase was officially added to New Mexico Territory without being assigned to a county. (U.S. Stat., vol. 10, ch. 245[1854]/p. 575; Van Zandt, 162; Walker and Bufkin, 21-22)

Non-County Area 2 lost all territory to DONA ANA; Non-County Area 2 eliminated. (N.M. Terr. Laws 1854, 4th assy. /p. 57)

Non-County Area 3 created from a remnant of GUADALUPE (original). (N.M. Terr. Laws 1903, 35th assy., ch. 69/pp. 127-131)

Non-County Area 3 lost all territory to creation of JEFFERSON (now SAN MIGUEL); Non-County Area 3 eliminated. (N.M. Laws 1923, 6th reg. sess., ch. 142/pp. 281-283)

OTERO created by New Mexico Territory from DOÑA ANA, LINCOLN, and SOCORRO. (N.M. Terr. Laws 1899, 33d assy., ch. 3/pp. 21-30)

QUAY created by New Mexico Territory from GUADALUPE (original) and UNION. (N.M. Terr. Laws 1903, 35th assy., ch. 8/pp. 16-20)

QUAY gained from SAN MIGUEL and UNION. (N.M. Terr. Laws 1907, 37th assy., ch. 62/pp. 123-124)

QUAY lost to creation of CURRY. (N.M. Terr. Laws 1909, 38th assy., ch. 6/pp. 9-13)

WASHINGTON (now QUAY) created from all of QUAY; QUAY eliminated. WASHINGTON existed for only one day before being renamed QUAY. This act and its companion the following day circumvented the constitutional prohibition against changing county boundaries by special or local law. (N.M. Laws 1923, 6th reg. sess., ch. 141/pp. 278-281)

WASHINGTON renamed QUAY. This act and its predecessor circumvented the constitutional prohibition against changing county boundaries by special or local law. (N.M. Laws 1923, 6th reg. sess., ch. 150/p. 331)

RIO ARRIBA established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between RIO ARRIBA and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

RIO ARRIBA recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

RIO ARRIBA gained from SAN MIGUEL, SANTA ANA, SANTA FE and Non-County Area 1, and exchanged with TAOS when all counties redefined; included parts of present Arizona, Nevada and New Mexico. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

RIO ARRIBA lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

RIO ARRIBA lost to SANTA FE [law repealed 1 January 1871]. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 11/pp. 36-38)

RIO ARRIBA gained from SANTA FE when the law of 18 January 1869 was repealed. (N.M. Terr. Laws 1869-1870, 19th assy., ch. 13/p.40)

RIO ARRIBA exchanged with TAOS. (N.M. Terr. Laws 1880, 24th assy., ch. 46/pp. 103-104)

RIO ARRIBA lost to creation of SAN JUAN. (N.M. Terr. Laws 1887, 27th assy., ch. 13/p. 38)

RIO ARRIBA lost to SANTA FE. (N.M. Terr. Laws 1888, 28th assy., ch. 127/pp. 301-302)

RIO ARRIBA lost to BERNALILLO. (N.M. Terr. Laws 1895, 31st assy., ch. 10/pp. 41-42)

RIO ARRIBA gained from SANTA FE. (N.M. Terr. Laws 1903, 35th assy., ch. 24/p. 35)

RIO ARRIBA lost small area [near Tres Piedras] to TAOS. (N.M. Terr. Laws 1905, 36th assy., ch. 11/pp. 39-40)

RIO ARRIBA gained from SANDOVAL when SANDOVAL was abolished, then immediately re-created on the same day with slightly different boundaries. Act passed 20 February 1905; took effect 8 May 1905. (N.M. Terr. Laws 1905, 36th assy., ch. 10/pp. 34-39)

Legislature authorized creation of RIO GRANDE (proposed) from part of CATRON and all of SOCORRO, and authorized changing the name of RIO GRANDE to SOCORRO. These acts attempted to circumvent the constitutional prohibition against changing county boundaries by special or local law and the attorney general filed action to prevent implementation of the statutes. Both proposals failed on 3 April 1928 when the New Mexico Supreme Court ruled the acts unconstitutional [no change]. (N.M. Laws 1927, 8th reg. sess., chs. 185-186/pp. 457-464; N.M. Constitution 1910, art. IV, sec. 2, in Swindler, 7:102-103; "State ex rel. Dow v. Graham," in N.M. Reports, 33:504-519; N.M. Stat. 1978, ch. 4, pamphlet 11, 4-28-1 "Socorro County Laws" 1927, ch. 185; Coan reprint, 20)

ROOSEVELT created by New Mexico Territory from CHAVES and GUADALUPE (original). (N.M. Terr. Laws 1903, 35th assy., ch. 7/pp. 12-16)

ROOSEVELT lost to creation of CURRY. (N.M. Terr. Laws 1909, 38th assy., ch. 6/pp. 9-13)

ROOSEVELT gained from CHAVES, lost to creation of DE BACA. (N.M. Laws 1917, 3rd reg. sess., ch. 11/pp. 41-48)

SANDOVAL created by New Mexico Territory from BERNALILLO. Act passed 10 March 1903; took effect 14 April 1903. (N.M. Terr. Laws 1903, 35th assy., ch. 27/pp. 37-43)

SANDOVAL was abolished, then immediately re-created on the same day with slightly different boundaries. Net result was SANDOVAL lost to RIO ARRIBA and SANTA FE. Act passed 20 February 1905; took effect 8 May 1905. (N.M. Terr. Laws 1905, 36th assy., ch. 10/pp. 34-39)

SANDOVAL lost to creation of LOS ALAMOS. A small area of SANDOVAL, between LOS ALAMOS and SANTA FE, was separated from the rest of the county, and SANDOVAL remained in two parts as of 2000. (N.M. Laws 1949, 19th reg. sess., ch. 134/pp. 319-321)

SAN JUAN (original, extinct) created by New Mexico Territory from TAOS; included parts of present Arizona, New Mexico, and Nevada. (N.M. Terr. Laws 1860-1861, 10th assy. /p. 16)

SAN JUAN (original, extinct) lost all territory to TAOS when the law creating SAN JUAN was repealed; SAN JUAN eliminated. (N.M. Terr. Laws 1861-1862, 11th assy. /p. 16)

SAN JUAN created by New Mexico Territory from RIO ARRIBA. (N.M. Terr. Laws 1887, 27th assy., ch. 13/p. 38)

SAN JUAN lost to McKINLEY. (N.M. Terr. Laws 1901, 34th assy., ch. 39/pp. 75-79)

SAN MIGUEL established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between SAN MIGUEL and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

SAN MIGUEL recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

SAN MIGUEL gained from SANTA FE and Non-County Area 1, and exchanged with BERNALILLO and TAOS when all counties redefined. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

SAN MIGUEL lost to SANTA FE. (N.M. Terr. Laws 1863-1864, 13th assy. /p. 88)

SAN MIGUEL had gained from BERNALILLO, SOCORRO, and VALENCIA. Though no law has been found authorizing this change, the definition for the creation of LINCOLN on 16 January 1869 depends on the SAN MIGUEL boundary having been extended southward as mapped. (Coan, 259)

SAN MIGUEL lost to MORA. (N.M. Terr. Laws 1882, 25th assy., ch. 86/pp. 176-177)

SAN MIGUEL exchanged with SANTA FE. (N.M. Terr. Laws 1882, 25th assy., ch. 83/p. 174)

Boundary between SAN MIGUEL and MORA redefined [no change]. (N.M. Terr. Laws 1888, 28th assy., ch. 37/p. 89)

SAN MIGUEL gained from SANTA FE. (N.M. Terr. Laws 1888, 28th assy., ch. 127/pp. 301-302)

SAN MIGUEL lost to creation of GUADALUPE (original). Act passed 26 February 1891, became effective 1 January 1893. (N.M. Terr. Laws 1891, 29th assy., ch. 88/pp. 175-180)

SAN MIGUEL lost to creation of UNION. Act passed 23 February 1893; took effect 1 January 1894. (N.M. Terr. Laws 1893, 30th assy., ch. 49/pp. 68-75)

SAN MIGUEL lost to creation of TORRANCE. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

SAN MIGUEL lost to TORRANCE. (N.M. Terr. Laws 1905, 36th assy., ch. 2/pp. 2-3)

SAN MIGUEL lost to QUAY. (N.M. Terr. Laws 1907, 37th assy., ch. 62/pp. 123-124)

JEFFERSON (now SAN MIGUEL) created from HARDING, Non-County Area 3, and all of SAN MIGUEL; Non-County Area 3 and SAN MIGUEL eliminated. JEFFERSON existed for only one day before being renamed SAN MIGUEL. This act and its companion the following day circumvented the constitutional prohibition against changing county boundaries by special or local law. (N.M. Laws 1923, 6th reg. sess., ch. 142/pp. 281-283)

JEFFERSON renamed SAN MIGUEL. This act and its predecessor circumvented the constitutional prohibition against changing county boundaries by special or local law. (N.M. Laws 1923, 6th reg. sess., ch. 151/p. 331)

SANTA ANA (extinct) established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between SANTA ANA and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

SANTA ANA (extinct) recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

SANTA ANA (extinct) gained from BERNALILLO and Non-County Area 1, exchanged with SANTA FE, and lost to RIO ARRIBA when all counties redefined; included parts of present Arizona, Nevada, and New Mexico. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 292)

SANTA ANA (extinct) lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

SANTA ANA (extinct) lost all territory to BERNALILLO; SANTA ANA eliminated. (N.M. Terr. Laws 1875-1876, 22d assy., ch. 8/pp. 38-40)

SANTA FE established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between SANTA FE and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

SANTA FE recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

SANTA FE gained from BERNALILLO, exchanged with SANTA ANA, and lost to RIO ARRIBA and SAN MIGUEL when all counties redefined. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

SANTA FE gained from SAN MIGUEL. (N.M. Terr. Laws 1863-1864, 13th assy. /p. 88)

SANTA FE gained from RIO ARRIBA [law repealed 1 January 1871]. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 11/pp. 36-38)

SANTA FE lost to RIO ARRIBA when the law of 18 January 1869 was repealed. (N.M. Terr. Laws 1869-1870, 19th assy., ch. 13/p.40)

SANTA FE gained from MORA, exchanged with BERNALILLO and SAN MIGUEL. (N.M. Terr. Laws 1882, 25th assy., ch. 83/p. 174)

SANTA FE gained from RIO ARRIBA, exchanged with BERNALILLO, lost to MORA and SAN MIGUEL. (N.M. Terr. Laws 1888, 28th assy., ch. 127/pp. 301-302)

SANTA FE lost to BERNALILLO. (N.M. Terr. Laws 1891, 29th assy., ch. 55/pp. 106-107)

SANTA FE lost to RIO ARRIBA. (N.M. Terr. Laws 1903, 35th assy., ch. 24/p. 35)

SANTA FE lost to creation of TORRANCE. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

SANTA FE gained from SANDOVAL when SANDOVAL was abolished, then immediately re-created on the same day with slightly different boundaries. Act passed 20 February 1905; took effect 8 May 1905. (N.M. Terr. Laws 1905, 36th assy., ch. 10/pp. 34-39)

SANTA FE lost to creation of LOS ALAMOS. (N.M. Laws 1949, 19th reg. sess., ch. 134/pp. 319-321)

SIERRA created by New Mexico Territory from DOÑA ANA, GRANT, and SOCORRO. (N.M. Terr. Laws 1884, 26th assy, ch. 109/pp. 223-225)

Territorial Legislature authorized SIERRA to gain from SOCORRO in "An Act to abolish the county of Sierra. . . . And creating a new county with different boundaries with the name of Sierra." Change was not approved by the U.S. Congress, as required by The Organic Act for the Territory of New Mexico (1850) [no change]. (N.M. Terr. Laws 1909, 38th assy., ch. 61/pp. 160-166; U.S. Stat., vol. 9, ch. 49[1850], sec. 7/p. 449; Coan, p. 19)

Boundary between SIERRA and GRANT redefined to run on the line between Township 12S and Township 13S [no mappable change]. (N.M. Laws 1917, 3rd reg. sess., ch. 57/pp. 178-179)

SIERRA gained from SOCORRO by a special election. (N.M. Compiled Stat. 1999, ch. 4, article 27, sec. 1/p. 43; election certificate filed with the Sierra County Clerk on 13 September 1951)

SOCORRO created by New Mexico Territory from Non-County Area 1; included parts of present Arizona and New Mexico. SOCORRO first mentioned in a 10 July 1851 establishing judicial districts, and on 06 January 1852 legislature authorized creation of DOÑA ANA from SOCORRO, however, no complete boundary definition is given for either county until 09 January 1852. (N.M. Terr. Laws 1851, 1st assy., 1st sess./p. 119; N.M. Terr. Laws 1851, 1st assy., 2d sess. /pp. 266, 292)

SOCORRO lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

SOCORRO gained from DOÑA ANA. (N.M. Terr. Laws 1866-1867, 16th assy. /p. 104)

SOCORRO lost to creation of GRANT. (N.M. Terr. Laws 1867-1868, 17th assy., ch. 20/p. 88)

SOCORRO had lost to SAN MIGUEL. Though no law has been found authorizing this change, the definition for the creation of LINCOLN on 16 January 1869 depends on the SAN MIGUEL boundary having been extended southward as mapped. (Coan, 259)

SOCORRO lost to creation of LINCOLN. (N.M. Terr. Laws 1868-1869, 18th assy., ch. 8/pp. 28-31)

SOCORRO lost to DOÑA ANA. (N.M. Terr. Laws 1869-1870, 19th assy., ch. 11/p. 36)

SOCORRO gained from DOÑA ANA. (N.M. Terr. Laws 1871-1872, 20th assy., ch. 2/pp. 4-5)

SOCORRO gained from DOÑA ANA. (N.M. Terr. Laws 1880, 24th assy., ch. 42/pp. 98-99)

SOCORRO lost to creation of SIERRA. Creation left a small portion of SOCORRO to the south of SIERRA, which remained until 24 February 1887 when it became part of DOÑA ANA. (N.M. Terr. Laws 1884, 26th assy., ch. 109/pp. 223-225)

SOCORRO lost to DOÑA ANA; eliminated separate part of SOCORRO. (N.M. Terr. Laws 1887, 27th assy., ch. 14/p. 39)

SOCORRO boundary with LINCOLN redefined to run along the public land survey line between ranges 8E and 9E [no mappable change]. (N.M. Terr. Laws 1893, 30th assy., ch. 20/pp. 36-37)

SOCORRO lost to creation of OTERO. (N.M. Terr. Laws 1899, 33d assy., ch. 3/pp. 21-30)

SOCORRO lost to creation of TORRANCE. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

SOCORRO lost to TORRANCE. (N.M. Terr. Laws 1905, 36th assy., ch. 2/pp. 2-3)

Territorial Legislature authorized SOCORRO to lose to SIERRA in "An Act to abolish the county of Sierra. . . . And creating a new county with different boundaries with the name of Sierra." Change was not approved by the U.S. Congress, as required by The Organic Act for the Territory of New Mexico (1850) [no change]. (N.M. Terr. Laws 1909, 38th assy., ch. 61/pp. 160-166; U.S. Stat., vol. 9, ch. 49[1850], sec.7/p. 449; Coan, p. 19)

SOCORRO exchanged with LINCOLN. (N.M. Terr. Laws 1909, 38th assy., ch. 112/pp. 326-327)

Boundary between SOCORRO and GRANT redefined to run on the line between Township 12S and Township 13S [no mappable change]. (N.M. Laws 1917, 3rd reg. sess., ch. 57/pp. 178-179)

SOCORRO lost to creation of CATRON. (N.M. Laws 1921, 5th reg. sess., ch. 28/pp. 37-45)

Legislature authorized the elimination of SOCORRO by the creation of RIO GRANDE (proposed), and authorized changing the name of RIO GRANDE to SOCORRO. These acts attempted to circumvent the constitutional prohibition against changing county boundaries by special or local law and the attorney general filed action to prevent implementation of the statutes. Both proposals failed on 3 April 1928 when the New Mexico Supreme Court ruled the acts unconstitutional [no change]. (N.M. Laws 1927, 8th reg. sess., chs. 185-186/pp. 457-464; N.M. Constitution 1910, art. IV, sec. 2, in Swindler, 7:102-103; "State ex rel. Dow v. Graham," in N.M. Reports, 33:504-519; N.M. Stat. 1978, ch. 4, pamphlet 11, 4-28-1 "Socorro County Laws" 1927, ch. 185; Coan reprint, 20)

SOCORRO lost to SIERRA by a special election. (N.M. Compiled Stat. 1999, ch. 4, article 28, sec. 1/p. 44; election certificate filed with the Sierra County Clerk on 13 September 1951)

TAOS established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." Competing claims to the eastern half of New Mexico resulted in an overlap between TAOS and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

TAOS recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

TAOS gained from Non-County Area 1, and exchanged with RIO ARRIBA and SAN MIGUEL when all counties redefined; included parts of present Arizona, Colorado, Nevada and New Mexico. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 291)

TAOS lost to creation of MORA. (N.M. Terr. Laws 1859-1860, 9th assy. /p. 76)

TAOS lost to creation of SAN JUAN (original, extinct). (N.M. Terr. Laws 1860-1861, 10th assy. /p. 16)

TAOS lost to creation of Colorado Territory. (U.S. Stat., vol. 12, pp. 172-177; Van Zandt, 141-144)

TAOS gained all of SAN JUAN (original, extinct) when the law creating SAN JUAN was repealed. (N.M. Terr. Laws 1861-1862, 11th assy. /p. 16)

TAOS lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

Boundary between TAOS and MORA redefined [no change]. (N.M. Terr. Laws 1867-1868, 17th assy., ch. 24/p. 106)

COLFAX attached to TAOS "for judicial purposes" [law repealed 24 January 1878]. (N.M. Terr. Laws 1875-1876, 22d assy., ch.6/pp. 35-37)

COLFAX detached from TAOS when the law of 14 January 1876 was repealed. (N.M. Terr. Laws 1878, 23d assy., ch. 9/p. 60)

TAOS exchanged with RIO ARRIBA. (N.M. Terr. Laws 1880, 24th assy., ch. 46/pp. 103-104)

TAOS gained small area [near Tres Piedras] from RIO ARRIBA. (N.M. Terr. Laws 1905, 36th assy., ch. 11/pp. 39-40)

The Republic of Texas officially established its boundaries: on the north and east, the Adams-Onis Treaty line; on the south the Rio Grande River; and on the west, from the source of the Rio Grande River north to the 42d parallel; included the entire eastern half of present New Mexico, and parts of present Colorado and Wyoming. BEXAR (Tex.) boundaries implicitly expanded to cover all resulting non-county area; territory claimed by Texas was officially a part of Mexico and remained in dispute, though neither the Republic of Texas nor Mexico established effective control of the area. Only the portion of Texas in present New Mexico is mapped. (Texas Repub. Laws 1836, 1st cong./p. 133; Donnell, 69; Frantz and Cox, 29, 31; Stephens and Holmes, 34)

Congress admitted the state of Texas to the Union; Republic of Texas eliminated. Dispute between Texas and Mexico over territory between the Nueces River and the Rio Grande River continued with Texas claiming the area as part of BEXAR (Tex.). (U.S. Stat., vol. 9, res. 1 [1845]/p. 108; Van Zandt, 122)

Kearny's Code of Laws was promulgated in Santa Fe for use in the occupied Mexican territory and established the seven original New Mexico counties of: BERNALILLO, RIO ARRIBA, SAN MIGUEL, SANTA FE, SANTA ANA, TAOS, and VALENCIA. State of Texas continued to claim its boundary extended as far west as the Rio Grande River resulting in an overlap between BEXAR (Tex.) and all seven New Mexico counties. (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

Treaty of Guadalupe-Hidalgo ended the war between Mexico and the United States. Area ceded by Mexico became Unorganized Federal Territory (non-county area) in the United States; included all of present California, Nevada, and Utah, and parts of present Arizona, Colorado, New Mexico, and Wyoming. Texas claimed the portion of Unorganized Federal Territory located east of the Rio Grand River as part of BEXAR (Tex.). (U.S. Stat., vol. 9, pp. 922-943; Parry, 102: 29-59; Van Zandt, 11, 28-29; Walker and Bufkin, 19, 20A)

Texas created SANTA FE (Tex., extinct) from BEXAR (Tex.); included parts of present Texas, Colorado, Kansas, New Mexico, Oklahoma, and Wyoming. Competing claims to the eastern half of New Mexico resulted in an overlap between SANTA FE (Tex.) and all seven New Mexico counties established in 1846 [see 22 December 1846 for simplified map of this overlap]; BEXAR continued to include a part of present New Mexico but no longer overlapped any New Mexico counties [not mapped]. (Texas Laws 1847, 2d leg., ch. 87/p. 95)

Texas created EL PASO (Tex.) and WORTH (Tex., extinct) from non-county area in Texas, both counties included parts of present New Mexico. EL PASO (Tex.) did not overlap any New Mexico counties; WORTH (Tex.) overlapped VALENCIA [not mapped]. (Texas Laws 1849, ed leg., reg. sess., ch. 29/p. 24)

State of Texas sold land in present Colorado, Kansas, New Mexico, Oklahoma, and Wyoming to the United States. Texas eliminated from present New Mexico. (U.S. Stat., vol. 9, ch. 49 [1850]/pp. 446-452 and appendix, sec. 10/pp. 1005-1006; Texas Laws 1850, 3d leg., 3d sess., ch. 2/p. 4; Van Zandt, 122)

TORRANCE created by New Mexico Territory from BERNALILLO, LINCOLN, SAN MIGUEL, SANTA FE, SOCORRO, and VALENCIA. Act passed 16 March 1903; took effect 1 January 1905. (N.M. Terr. Laws 1903, 35th assy., ch. 70/pp. 132-134)

TORRANCE gained from SAN MIGUEL, SOCORRO, and VALENCIA. (N.M. Terr. Laws 1905, 36th assy., ch. 2/pp. 2-3)

UNION created by New Mexico Territory from COLFAX, MORA, and SAN MIGUEL. Act passed 23 February 1893; took effect 1 January 1894. (N.M. Terr. Laws 1893, 30th assy., ch. 49/pp. 68-75)

UNION boundary was clarified to correct an "uncertainty, ambiguity and apparent contradiction in the language" of the 1 January 1894 law [no change]. (N.M. Terr. Laws 1895, 31st assy., ch. 12/p. 43)

UNION lost to creation of QUAY. (N.M. Terr. Laws 1903, 35th assy., ch. 8/pp. 16-20)

UNION lost to QUAY. (N.M. Terr. Laws 1907, 37th assy., ch. 62/pp. 123-124)

UNION lost to creation of HARDING. (N.M. Laws 1921, 5th reg. sess., ch. 48/pp. 106-107)

Treaty of Guadalupe-Hidalgo ended the war between Mexico and the United States. Area ceded by Mexico became Unorganized Federal Territory (non-county area) in the United States; included all of present California, Nevada, and Utah, and parts of present Arizona, Colorado, New Mexico, and Wyoming. Texas claimed the portion of Unorganized Federal Territory located east of the Rio Grand River as part of BEXAR (Tex.); Part of the international boundary with Mexico was in dispute. Map shows only the portion of Unorganized Federal Territory in present New Mexico. (U.S. Stat., vol. 9, pp. 922-943; Parry, 102: 29-59; Van Zandt, 11, 28-29; Walker and Bufkin, 19, 20A)

The United States created New Mexico Territory from Unorganized Federal Territory and land purchased from the state of Texas; all that portion of Unorganized Federal Territory lying outside the boundaries of the seven original counties established under Kearny's Code became Non-County Area 1 in New Mexico Territory. (U.S. Stat., vol. 9, ch. 49[1850]/pp. 446-452; Baldwin, 117-137; Van Zandt, 28-29, 162-165)

VALENCIA established as one of seven original New Mexico counties under Kearny's Code of Laws for the occupied Mexican territory. No written definitions given for the counties, boundaries were shown on the "Map of New Mexico Territory made by order of Brig. Gen. S. W. Kearny under instructions from Lieut. W. H. Emory, U.S.T.E. by Lieut's S.W. Abert and W.G. Peck, U.S.T.E. 1846-7." No southern limit given for VALENCIA [estimated line]. Competing claims to the eastern half of New Mexico resulted in an overlap between VALENCIA and BEXAR (Tex.). (Kearny's Code 1846, "Courts and Judicial Powers,” secs. 5-7/p. 49; Abel, Map #2; Coan, 252; Williams, 108-109)

VALENCIA recognized by the General Assembly of the Territory of New Mexico which convened December 1847 prior to formal designation of New Mexico Territory by the United States Congress. (N.M. Terr. Laws 1847, pp. 37-39)

VALENCIA gained from Non-County Area 1, lost to creation of SOCORRO, and lost to BERNALILLO when all counties redefined; included parts of present Arizona, Nevada, and New Mexico. (N.M. Terr. Laws 1851, 1st assy., 2d sess. /p. 292)

VALENCIA lost to creation of Arizona Territory. (U.S. Stat., vol. 12, pp. 664-665; Van Zandt, 165)

VALENCIA had lost to SAN MIGUEL. Though no law has been found authorizing this change, the definition for the creation of LINCOLN on 16 January 1869 depends on the SAN MIGUEL boundary having been extended southward as mapped. (Coan, 259)

New Mexico: Individual County Chronologies