New York Atlas of Historical County Boundaries
John H. Long, Editor; Peggy Tuck Sinko, Associate Editor; Kathryn Ford Thorne, Historical Compiler; Douglas Knox, Book Digitizing Director; Emily Kelley, Research Associate; Laura Rico-Beck, GIS Specialist and Digital Compiler; Peter Siczewicz, ArcIMS Interactive Map Designer; Robert Will, Cartographic Assistant
Copyright The Newberry Library 2008
10 April 1606
King James I chartered two Virginia Companies, headquartered in different English cities, to establish colonies along the coast of North America, including islands within 100 miles and, by implication, extending inland 100 miles: the Virginia Company of London, assigned coast between 34 degrees and 41 degrees north latitude; and the Virginia Company of Plymouth, assigned coast between 38 degrees and 45 degrees north latitude, including present New York. Colonies of the two companies were to be at least 100 miles apart, even where the grants overlapped. (Paullin, pl. 42; Swindler, 10:17-23; Van Zandt, 92)
1613
The Dutch established trading posts on the Hudson River and claimed jurisdiction between the Connecticut and Delaware Rivers, including present southern New York and western Connecticut. (Van Zandt, 74)
3 November 1620
King James I replaced the charter to the Virginia Company of Plymouth with a charter for a Council for New England to establish colonies in a region between 40 degrees and 48 degrees north latitude and extending from the Atlantic to the Pacific Ocean, including all of present New York. (Swindler, 5:16-26)
by August 1624
The Dutch West India Company founded the colony of New Netherland, including the first permanent European settlement in the area of present New York at Fort Orange (now Albany), followed within two years by the establishment of New Amsterdam (now New York City). Over the next two and a half decades, conflict developed between the Dutch and the English as settlers from both countries moved into Long Island and the area of present western Connecticut. (Flick, 1:234-235, 238; 2:40-48)
4 March 1629
[4 March 1628/1629] King Charles I chartered the Massachusetts Bay Company to establish a colony in the region stretching from three miles north of the Merrimack River ("to the Northward of any and every Parte thereof") to three miles south of the Charles River and extending westward from the Atlantic coast to the Pacific Ocean. Area included present central New York. (Swindler, 5:32-42; Andrews, 1:359)
by 3 June 1631
The Dutch established the first European settlement on the west side of Delaware Bay at Zwanendael (now Lewes, Del.). (Munroe, Colonial Delaware, 9-12)
March 1638
The New Sweden Company established the first permanent European settlement on the Delaware River at Fort Christina (now Wilmington, Del.). New Sweden claimed and, for the most part, controlled the lower Delaware River region (parts of present Delaware, New Jersey, and Pennsylvania), but settled few colonists there. (McCormick, 12; Munroe, Colonial Delaware, 16; Pomfret, Colonial New Jersey, 4)
19 September 1650
Connecticut and New Netherland agreed on a boundary in the Hartford Treaty, never ratified by England but observed by both sides until war erupted between the English and the Dutch in 1652. This agreement divided Long Island by a line extending due south from Oyster Bay and, on the mainland, prescribed a line 20 miles long running due north from Greenwich Bay, but specified no other limits. Conflict over uncertain colonial limits continued until the Duke of York captured New Netherland in 1664. (Bowen, 17-18; Flick, 2:50-57)
23 April 1662
King Charles II granted Connecticut a charter as a self-governing corporate colony, consolidating Hartford and other settlements on the Connecticut River with New Haven and other coastal settlements into a single colony. Limit on the south was Long Island Sound and, on the west, was the Pacific Ocean ("South Sea"), thereby overlapping New Netherland. (Bowen, 32; Swindler, 2:135-136)
7 May 1662
HAMPSHIRE (Mass.) created from non-county area in Massachusetts Colony (towns of Springfield, Northampton, Hadley, and all territory within 30 miles). HAMPSHIRE included a small area in present New York known as "Boston Corner." Eastern boundary was indefinite. (Mass. Recs., vol. 4, pt. 2:52)
12 March 1664
[12 March 1663/1664] King Charles II granted the Duke of York the following: all territory between the Connecticut and Delaware Rivers; the islands of Long Island, Martha's Vineyard, and Nantucket; and the area between the Kennebec and St. Croix Rivers extending inland from the Atlantic coast to the St. Lawrence River. This not only covered New Netherland, still occupied by the Dutch, but also included all or part of present New York; Quebec, Canada; Maine; New Jersey; Vermont; Connecticut; and Massachusetts. (Parry, 13:136; Swindler, 4:278-280; Williamson, W.D., 1:446)
24 June 1664
New Jersey was created when the Duke of York sold the area (not yet occupied by the English) to John Berkeley and George Carteret for a proprietary colony. The area was defined as all land east of the Delaware River, west of the Hudson River, and south of a straight line from the intersection of the Delaware River at the parallel of 41 degrees, 40 minutes north latitude to the Hudson River at the parallel of 41 degrees north latitude. Actual transfer was in August 1665. The straight line between the rivers ran through an area unsettled by colonists and was not demarcated. (Pomfret, 22; Swindler, 6:375-377; Van Zandt, 79)
29 August 1664
The Duke of York's forces captured New Amsterdam from the Dutch, swiftly took control of the rest of New Netherland, and renamed the province New York. Territory included present New Jersey, New York, and Vermont. In October 1664, the Duke of York's forces captured Fort Casimir (now New Castle, Del.), thereby completing their conquest of New Netherland and bringing the west side of Delaware Bay (also claimed by Maryland), including present Delaware and Pennsylvania, under the de facto control of the Duke and New York. The conquest was confirmed in 1667 by the Peace of Breda. (Flick, 2:80; Munroe, History of Delaware, 30-31)
Fall 1664
In the fall of 1664, royal commissioners tried to settle the implicit conflict between the recent grant (12 March 1663/1664) of New York to the Duke of York and the western limit of Massachusetts, as specified in its 1629 charter, by proposing a boundary line running 20 miles east of the Hudson River. Never formalized, this proposal was widely accepted in principle but did not prevent a long, serious dispute between the two colonies. (Schwarz, 20; Van Zandt, 70)
1664
Connecticut and New York agreed that New York would have sole jurisdiction over Long Island and that their mutual boundary would run north-northwest from the Mamaroneck River to the southern line of Massachusetts. While effective locally, the agreement was never confirmed in England. The line was never surveyed and was not well observed far inland. (Bowen, 17, 70-72)
Shire of Yorkshire created as the first large governmental unit (not a county) organized in New York; jurisdiction included Long Island, Staten Island, Manhattan, and extended up the east side of the Hudson River [not mapped]. (N.Y. Col. Laws, 1:xi)
5 September 1665
CORNWALL (extinct) created by New York to cover all of the Duke of York's grant between the Kennebec and St. Croix Rivers in present Maine and Quebec, Canada. (Williamson, W.D., 1:421)
1665
The town of Rye came under Connecticut jurisdiction as a result of the intercolonial agreement of 1664. (Bowen, 17, 70-72)
10 May 1666
FAIRFIELD (Conn.) created by Connecticut as one of its four original counties; part of its western limit was not clearly defined, but included part of New York (town of Rye). (Conn. Col. Recs., 2:34-35)
21 July 1667
The Peace of Breda, between England and France and the Netherlands, confirmed the English conquest of New York from the Dutch in 1664. (Farnham, 7:311, 314; Parry, 10:231)
19 May 1669
HAMPSHIRE (Mass.) gained from Connecticut when the town of Westfield (now Southwick) was created from the town of Springfield. Part of Westfield extended into Connecticut, the result of disagreement over the line between Massachusetts and Connecticut. Area within present New York was unchanged. (Bowen, 53-58; Mass. Recs., vol. 4, pt. 2:432)
August 1673
Dutch forces recaptured the territory of old New Netherland, including eastern New York. (Flick, 2:93)
12 September 1673
After completing their re-conquest of New York in August 1673, the Dutch created HOARKILL (later DEALE, now SUSSEX, Del.) and NEW AMSTEL (now NEW CASTLE, Del.) in present Delaware, and UPLAND (Del., extinct) in present Delaware and Pennsylvania [no inland limits were specified]. These 3 counties became dependent on New York in 1674. (Docs. of N.Y., 12:507-508; George, Nead, and McCamant, 453-454; Reed, 22)
by 7 October 1673
Massachusetts, relying on a new survey of its northern limit and responding to the Dutch capture of New York in August 1673, claimed some of the Duke of York's grant east of the Kennebec River in present Maine (including the Pemaquid settlement) and created an unnamed county that on 27 May 1675 was named DEVONSHIRE (Mass., extinct). This unnamed county overlapped part of CORNWALL (extinct), but the Duke of York did not recognize the Massachusetts claim. (Mass. Recs., 5:16; Reid, Maine, 138; Williamson, W.D., 1:443)
3 June 1674
HAMPSHIRE (Mass.) gained from Connecticut when the town of Suffield was created. Suffield was entirely within present Connecticut, the result of uncertain geographical knowledge and disagreement over the boundary between the colonies. Area within present New York was unchanged. (Bowen, 53-58; Mass. Recs., 5:13)
29 June 1674
Following the Treaty of Westminster (9 February 1673/1674) that ended the Anglo-Dutch war and restored New York to the English, King Charles II regranted to the Duke of York all territory he had granted on 12 March 1663/1664. (Parry, 13:136; Swindler, 4:282; Williamson, W.D., 1:446)
by 6 November 1674
In the fall of 1674, the Dutch returned New York and the Delaware River settlements, including HOARKILL (later DEALE, now SUSSEX, Del.), NEW AMSTEL (now NEW CASTLE, Del.), and UPLAND (Del., extinct) to the Duke of York in accordance with the Treaty of Westminster (9 February 1673/1674). By 6 November 1674 these counties were made dependent on New York, although Maryland also claimed the area. (Docs. of N.Y., 12:515; George, Nead, and McCamant, 454; Parry, 13:136)
by 11 November 1674
NEW AMSTEL (Del.) was renamed NEW CASTLE (Del.). (Docs. of N.Y., 12:515)
18 May 1675
FAIRFIELD (Conn.) gained town of Woodbury in Connecticut; area within New York was unchanged. (Conn. Col. Recs., 2:253)
Fall 1675
In the fall of 1675, CORNWALL (extinct) and DEVONSHIRE (Mass., extinct) were apparently eliminated when war broke out between the Abnaki Indians and the English in present Maine. (Williamson, W.D., 1:446)
1 July 1676
George Carteret and the other New Jersey proprietors executed the Quintipartite Deed to divide New Jersey into two distinct colonies, East New Jersey and West New Jersey. Both colonies were unorganized and technically were non-county areas. The two colonies included parts of present New York. (Snyder, 9, 13; Swindler, 6:398; Van Zandt, 79)
22 September 1676
The Duke of York's laws were extended from New York to the Delaware region; HOARKILL (later DEALE, now SUSSEX, Del.), NEW CASTLE (Del.), and UPLAND (Del., extinct) were formally placed under the Duke of York's laws. (Docs. of N.Y., 12:561-563; Reed, 13)
12 November 1678
NEW CASTLE (Del.) gained from UPLAND (Del., extinct). (Armstrong, 119, 198)
21 June 1680
ST. JONES (now KENT, Del.) created under the authority of the Duke of York in present Delaware from NEW CASTLE (Del.) and HOARKILL (later DEALE, now SUSSEX, Del.); no inland limits were specified. (Docs. of N.Y., 12:654, 664, 666-667; Reed, 12)
by 15 June 1681
HOARKILL renamed DEALE (now SUSSEX, Del.). (Reed, 13; Turner, 54)
June 1681
UPLAND (Del., extinct) was eliminated when the newly chartered proprietary colony of Pennsylvania instituted government for all territory on the west side of the Delaware River from twelve miles north of New Castle to 42 degrees north latitude. (Armstrong, 196; Swindler, 8:243)
1681
The creation of the county-like courts of Burlington and Salem in the southern portion of West New Jersey left the northern portion of the colony completely unorganized as a non-county area. A small portion of West New Jersey was in present New York. (Snyder, 12)
24 August 1682
DEALE (now SUSSEX, Del.), NEW CASTLE (Del.), and ST. JONES (now KENT, Del.) eliminated from New York when the Duke of York transferred present Delaware to William Penn. (Pa. Arch., 2d ser., 5:739-744)
7 March 1683
[7 March 1682/1683] BERGEN (N.J.) and ESSEX (N.J.) created as two of four original counties in East New Jersey; BERGEN and ESSEX included parts of New York. East New Jersey eliminated from New York. (Shaw, 1:212, 231; Snyder, 10-11, 29-31; Wall and Pickersgill, 1:63)
16 May 1683
HAMPSHIRE (Mass.) gained from Connecticut when town of Enfield was created within present Connecticut. Area within New York was unchanged. (Bowen, 53-58; Mass. Recs., 5:410-411)
1 November 1683
ALBANY created from non-county area in New York; northern limit was not defined. (N.Y. Col. Laws, ch. 4/1:122)
CORNWALL (extinct) re-created to cover all of the Duke of York's grant in present Maine and Quebec, including the Pemaquid settlement governed since 1674 by Massachusetts. (N.Y. Col. Laws, ch. 4/1:122)
DUKES (extinct) created to cover the 1674 grant to the Duke of York of islands in Massachusetts, including Martha's Vineyard, Nantucket, and Elizabeth Islands. (N.Y. Col. Laws, ch. 4/1:122)
DUTCHESS, ORANGE, and ULSTER created from non-county area in New York. (N.Y. Col. Laws, ch. 4/1:122)
KINGS, NEW YORK, QUEENS, RICHMOND, SUFFOLK, and WESTCHESTER created from Yorkshire, which had been organized in 1664. (N.Y. Col. Laws, ch. 4/1:122)
Non-County Area 1 (Brothers Islands and Hulett's [now Rikers] Island); Non-County Area 2 (the Oyster Islands [now Ellis, Liberty, and Governors Islands]); and Non-County Area 3 (City I., Hart I., Manursing I., and other small islands in Long Island Sound) were created from Yorkshire. (N.Y. Col. Laws, ch. 4/1:122)
28 November 1683
WESTCHESTER and Non-County Area 3 both gained from FAIRFIELD (Conn.) when the provincial boundary between Connecticut and New York was adjusted; FAIRFIELD (Conn.) eliminated from New York. (Bowen, 73-74; Van Zandt, 72-73)
8 January 1687
[8 January 1686/1687] ESSEX (N.J.) gained non-county in West New Jersey when the absentee governors of East and West New Jersey agreed on a new division between their colonies. (Snyder, 9, 31)
Spring 1687
In the spring of 1687, CORNWALL was eliminated when the area was incorporated into the Dominion of New England, a new province into which New York, New Jersey, and the New England colonies eventually were consolidated. (Barnes, 69-70; N.H. Early Laws, 1:166, 171)
11 August 1688
New York was formally incorporated into the Dominion of New England, in accordance with the new royal governor's second commission (7 April 1688) and instructions (16 April 1688) from King James II. No changes were made to counties. (Docs. of N.Y., 3:537, 543, 554)
5 September 1688
West New Jersey gained from ESSEX (N.J.) and SOMERSET (N.J.) when the absentee governors of East and West New Jersey agreed on a compromise boundary between their colonies from the north end of the Keith Line (1687) eastward to New York. (Snyder, 9, 31)
20 March 1689
Royal officials lost control of New York when local militia captured the fort in New York City (Leisler's Rebellion). Regular government was reinstituted with the arrival of a new royal governor (19 March 1690/1691). (Andrews, 3:125, 133)
18 April 1689
Upon learning of the Glorious Revolution (replacement of King James II by King William III and Queen Mary II) in England, Bostonians imprisoned the royal governor and others, thereby ending the Dominion of New England. Over the next months New York and the other colonies that had been united to form the Dominion had to resume self-government. (Craven, 224; Morris and Kelly, pl. 11)
1 October 1691
All county boundaries were redefined. (N.Y. Col. Laws, ch. 17/1:268)
Changes were:
DUTCHESS lost to creation of Non-County Area 4.
NEW YORK gained all of Non-County Area 2 (the Oyster Islands [now Ellis, Liberty, and Governors Islands]); Non-County Area 2 eliminated.
QUEENS gained all of Non-County Area 1 (the Brother Islands and Huletts [now Rikers] Island); Non-County Area 1 eliminated.
7 October 1691
The province of Massachusetts Bay gained all of DUKES (the islands of Nantucket, Elizabeth, and Martha's Vineyard) when King William III and Queen Mary II issued a new charter for Massachusetts Bay and enlarged its jurisdiction to encompass territory that had been part of New York; DUKES eliminated. (Swindler, 5:80)
20 April 1693
DUTCHESS was attached to ULSTER for administrative and judicial purposes; ORANGE was attached to NEW YORK for administrative and judicial purposes. (O'Callaghan, 1:201)
by 31 December 1698
ORANGE was fully organized, detached from NEW YORK. (O'Callaghan, 1:467)
18 October 1701
ULSTER gained from ORANGE; DUTCHESS's attachment to ULSTER was confirmed. (N.Y. Col. Laws, ch. 94/1:453)
1708
DUTCHESS was fully organized, detached from ULSTER. (N.Y. Col. Laws, ch. 94/1:453)
12 November 1709
ORANGE gained from ULSTER. (N.Y. Col. Laws, ch. 202/1:686)
21 January 1710
[21 January 1709/1710] BERGEN (N.J.) gained from ESSEX (N.J.); ESSEX eliminated from New York. The non-county area of West New Jersey lost to BURLINGTON (N.J.); area within New York was unchanged. (Snyder, 30-32)
11 March 1714
[11 March 1713/1714] HUNTERDON (N.J.) created from BURLINGTON (N.J.) and non-county area in West New Jersey; HUNTERDON included territory in New York. (Paterson, 4; Snell, 196; Snyder, 32)
27 May 1717
ALBANY gained from DUTCHESS and Non-County Area 4. (N.Y. Col. Laws, ch. 333/1:915)
25 July 1719
New Jersey and New York agreed on the location of the northwestern terminus of their boundary, to be called Station Point, on the Delaware River about the parallel of 41 degrees, 40 minutes north latitude, as specified in the 1664 deed from the Duke of York. The location of Station Point was demarcated but the line from there to the Hudson River was not surveyed. (Snyder, 13)
10 July 1731
HAMPSHIRE (Mass.) lost to creation of WORCESTER (Mass.); area within present New York was unchanged. (Mass. Col. Acts, vol. 2, ch. 8 [1730-1731], sec. 1/p. 584)
15 March 1739
[15 March 1738/1739] MORRIS (N.J.) created from HUNTERDON (N.J.) and ESSEX (N.J.); MORRIS included territory in New York. HUNTERDON eliminated from New York. (Paterson, 12-13; Snyder, 32)
16 January 1742
[16 January 1741/1742] HAMPSHIRE (Mass.) lost to WORCESTER (Mass.) when town of Western (now Warren) was created from towns of Brookfield, Brimfield, and Kingsfield; area within present New York was unchanged. (Mass. Col. Acts, vol. 2, ch. 17 [1741-1742], sec. 2/p. 1088)
May 1749
HAMPSHIRE (Mass.) lost towns of Enfield, Somers (formerly part of Enfield), and Suffield to Connecticut. Area within present New York was unchanged. (Bowen, 62; Hooker, 22, 26)
8 June 1753
SUSSEX (N.J.) created from MORRIS (N.J.); SUSSEX included territory in New York. MORRIS eliminated from New York. (Paterson, 15; Snyder, 34)
30 June 1761
BERKSHIRE (Mass.) created from HAMPSHIRE (Mass.). BERKSHIRE included a small area in present New York (Boston Corner) that had previously been part of HAMPSHIRE (Mass.), which was eliminated from present New York. (Mass. Col. Acts, vol. 4, ch. 33 [1760-1761], sec. 1/p. 432)
7 October 1763
King George III, as part of his Proclamation of 1763, created the new province of Quebec in Canada, implicitly setting the northern limit of New York at the parallel of 45 degrees north latitude from the Atlantic-St. Lawrence watershed westward to the St. Lawrence River. ALBANY's northern limit was implicitly set at this new northern limit [not mapped]. (Cappon, Petchenik, and Long, 1, 77, 90; Shortt and Doughty, 119-120)
20 July 1764
ALBANY implicitly gained all of present Vermont when King George III established the boundary between New York and New Hampshire along the west bank of the Connecticut River, north of Massachusetts [western limit not defined]. (Slade, 13-19; Van Zandt, 63)
3 July 1766
CUMBERLAND (extinct) created from ALBANY; CUMBERLAND was located entirely within present Vermont. (N.Y. Col. Laws, ch. 1297/4:904)
26 June 1767
ALBANY gained all of CUMBERLAND; CUMBERLAND eliminated when the act that created it was annulled. (N.Y. Col. Laws, ch. 1297/4:903)
19 March 1768
CUMBERLAND (extinct) re-created from ALBANY in present Vermont. Boundaries were slightly different from those CUMBERLAND originally had in 1766. (N.Y. Col. Laws, ch. 1559/5:400)
30 June 1768
BERKSHIRE (Mass.) lost to HAMPSHIRE (Mass.) when town of Worthington was created from Plantation #3. Area within present New York was unchanged. (Mass. Col. Acts, vol. 4, ch. 16 [1768], sec. 1/p. 1028)
31 December 1768
ORANGE gained the western half of the Hudson River [not mapped]. QUEENS gained islands in Long Island Sound that had not previously been part of any county [not mapped]. WESTCHESTER gained all of Non-County Area 3 (Hart Island, City Island, Manursing Island, and other small islands in Long Island Sound); Non-County Area 3 eliminated. (N.Y. Col. Laws, ch. 1376/4:1063)
16 March 1770
GLOUCESTER (extinct) created from ALBANY; GLOUCESTER was located entirely in present Vermont. (N.Y. Col. Laws, ch. 1559/5:401)
12 March 1772
CHARLOTTE (now WASHINGTON) and TRYON (now MONTGOMERY) created from ALBANY. TRYON's western boundary is estimated, since no western limit was specified; New York's western boundary was not definitively established until 1782. (N.Y. Col. Laws, ch. 1534/5:321)
24 March 1772
CHARLOTTE (now WASHINGTON) exchanged with GLOUCESTER (extinct). CUMBERLAND (extinct) gained from ALBANY and CHARLOTTE, lost to GLOUCESTER (extinct). (N.Y. Col. Laws, ch. 1559/5:402)
18 May 1773
Massachusetts and New York agreed on the course of their boundary (a straight line roughly parallel to and 20 miles east of the Hudson River), thereby ending nearly a century of uncertainty and dispute. The line was demarcated in 1787. (Cappon, Petchenik, and Long, 89; Schwarz, 220; Van Zandt, 70)
1 September 1773
ORANGE gained from BERGEN (N.J.) and SUSSEX (N.J.), and ULSTER gained from SUSSEX (N.J.) when King George III approved the boundary between New Jersey and New York, as determined by a commission appointed in 1769 at the joint request of the two colonies after decades of dispute. (Pratt, 2:789; Snyder, 13-14; Van Zandt, 76)
12 January 1774
LITCHFIELD (Conn.) gained the town of Westmoreland, a town created by Connecticut in northeastern Pennsylvania and a narrow strip of New York about 3 miles wide. Connecticut claimed the area based on its 1662 charter. Although LITCHFIELD encroached slightly into New York, the dispute was between Connecticut and Pennsylvania. (Cappon, Petchenik, and Long, 17, 92; Conn. Col. Recs., 13:427, 14:218)
9 March 1774
ULSTER gained from ALBANY. (N.Y. Col. Laws, ch. 1665/5:662)
22 June 1774
King George III approved the Quebec Act, which implicitly set the northern limit of western New York along the St. Lawrence River upstream from the parallel of 45 degrees north latitude and through Lakes Ontario and Erie. (Cappon, Petchenik, and Long, 90)
August 1774
New York and Pennsylvania agreed to define their boundary as the Delaware River up to the parallel of 42 degrees north latitude, and thence to their western limits. The point where the 42d parallel intersects the Delaware River was marked in November 1774, the remainder of the line in 1787. (Pratt, 1:241-248)
1 April 1775
CHARLOTTE (now WASHINGTON) gained from ALBANY, exchanged with CUMBERLAND (extinct). ALBANY exchanged with CUMBERLAND (extinct). (N.Y. Col. Laws, ch. 1719/5:779)
11 May 1775
LITCHFIELD (Conn.) gained territory in Pennsylvania and New York when Connecticut enlarged the town of Westmoreland to the Fort Stanwix Indian Treaty line. (Cappon, Petchenik, and Long, 17, 92; Conn. Col. Recs., 15:13)
14 December 1775
LITCHFIELD (Conn.) gained territory from New York and exchanged territory with Pennsylvania when Connecticut reduced the area of the town of Westmoreland. (Cappon, Petchenik, and Long, 17, 92; Conn. Col. Recs., 15:197-198)
4 July 1776
New York became an independent state. (Declaration of Independence)
10 October 1776
WESTMORELAND (Conn., extinct) created from LITCHFIELD (Conn.) when Connecticut removed the town of Westmoreland from LITCHFIELD and made it "a distinct County;" WESTMORELAND was located entirely within Pennsylvania and a narrow strip of New York about 3 miles wide. LITCHFIELD (Conn.) eliminated from New York and Pennsylvania. (Cappon, Petchenik, and Long, 17, 92; Conn. St. Recs., 1:7)
15 January 1777
Vermont declared its independence from New York and became an independent republic. ALBANY and CHARLOTTE (now WASHINGTON) lost territory and were eliminated from Vermont. CUMBERLAND and GLOUCESTER were eliminated. (Slade, 70-73; Van Zandt, 64; C. Williamson, 82-84, map facing 95, 100-102, 112-113)
23 June 1779
BERKSHIRE (Mass.) lost to HAMPSHIRE (Mass.) when town of Cummington was created from Plantation #5. Area within present New York was unchanged. (Mass. Col. Acts, vol. 5, ch. 6 [1779-1780], sec. 1/pp. 1072-1073)
26 June 1781
Vermont attempted to annex part of New York east of the Hudson River (the so-called West Union); inhabitants in the area favored Vermont's township form of government, while Vermont hoped to gain bargaining power through expansion. New York did not lose control of the area. The West Union included parts of ALBANY and CHARLOTTE (now WASHINGTON); BENNINGTON (Vt.) overlapped part of ALBANY, and RUTLAND (Vt.) overlapped part of CHARLOTTE. (Vt. State Papers, 13:45-46; Newton, 83-87; Williamson, C., 101-102)
23 February 1782
Vermont's overlap of New York ended when Vermont gave up its attempt to annex the West Union. BENNINGTON (Vt.) overlap of ALBANY ended, and RUTLAND (Vt.) overlap of CHARLOTTE (now WASHINGTON) ended. (Vt. State Papers, 3, pt. 2: 67-68)
29 October 1782
New York ceded to the United States any claim to territory west of the meridian of the western end of Lake Ontario, thereby defining its western boundary. (Cappon, Petchenik, and Long, 130; Van Zandt, 75)
30 December 1782
WESTMORELAND (Conn.) eliminated when a special congressional court of arbitration ruled that the territory belonged in Pennsylvania, not Connecticut. (Susquehannah Co. Papers, 7: xxxiii, 245)
12 March 1783
BERKSHIRE (Mass.) lost to HAMPSHIRE (Mass.) when town of Middlefield was created from Worthington, Chester, Partridgefield (now Peru), Becket, Washington, and Prescott's Grant (now Middlefield). Area within present New York was unchanged. (Mass. Acts 1783, ch. 19, sec. 1/p. 228)
3 September 1783
Commissioners from Great Britain and the United States signed the Treaty of Paris (ratifications exchanged 12 May 1784) ending the War of the American Revolution, recognizing American independence, and defining the northern U.S. boundary as the St. Croix River-Atlantic watershed-45th parallel-St. Lawrence River-Great Lakes line, thereby fixing New York's northern and western limits. (Parry, 48:481, 487, 491-492; Van Zandt, 12)
2 April 1784
CHARLOTTE renamed WASHINGTON; TRYON renamed MONTGOMERY. (N.Y. Laws 1784, 7th sess., ch. 17/p. 21)
9 February 1785
BERKSHIRE (Mass.) lost to HAMPSHIRE (Mass.) when town of Rowe was created from the Myrifield Grant and non-town territory. Area within present New York was unchanged. (Mass. Acts 1785, ch. 2, sec. 1/p. 230)
4 April 1786
COLUMBIA created from ALBANY. (N.Y. Laws 1786, 9th sess., ch. 28/p. 49)
16 December 1786
Massachusetts relinquished any claim (based on its original 1629 charter) to jurisdiction in western New York. (Van Zandt, 75)
7 March 1788
CLINTON created from WASHINGTON. DUTCHESS gained all of Non-County Area 4; Non-County Area 4 eliminated. New York, refusing to recognize the independence of Vermont and the elimination of CUMBERLAND (extinct) in 1777, attempted unsuccessfully to adjust the former boundary of ALBANY and WASHINGTON with CUMBERLAND (extinct) in Vermont, but to no effect. (N.Y. Laws 1788, 11th sess., ch. 63/pp. 746-747)
27 January 1789
ONTARIO created from MONTGOMERY. (N.Y. Laws 1789, 12th sess., ch. 11/p. 10)
7 February 1791
RENSSELAER and SARATOGA created from ALBANY. WASHINGTON gained from ALBANY. (N.Y. Laws 1791, 14th sess., ch. 4/p. 201)
16 February 1791
HERKIMER, OTSEGO, and TIOGA created from MONTGOMERY. (N.Y. Laws 1791, 14th sess., ch. 10/p. 206)
4 March 1791
The state of Vermont was admitted to the Union, bringing to an end New York's attempt to regain control of Vermont. (U.S. Stat., vol. 1, ch. 7[1791]/p. 191; Slade, 193; Cappon, Petchenik, and Long, 91)
9 March 1793
BERKSHIRE (Mass.) lost to HAMPSHIRE (Mass.) when town of Hawley gained from non-town area called Plantation #7. Area within present New York was unchanged. (Mass. Acts 1793, ch. 18, sec. 1/p. 242)
5 March 1794
ONONDAGA created from HERKIMER and TIOGA. (N.Y. Laws 1794, 17th sess., ch. 18/p. 491)
1 June 1795
SCHOHARIE created from ALBANY and OTSEGO. (N.Y. Laws 1795, 18th sess., ch. 42/p. 588)
18 March 1796
STEUBEN created from ONTARIO. (N.Y. Laws 1796, 19th sess., ch. 29/p. 667)
10 March 1797
DELAWARE created from OTSEGO and ULSTER. (N.Y. Laws 1797, 20th sess., ch. 33/p. 39)
31 March 1797
MONTGOMERY gained from HERKIMER. (N.Y. Laws 1797, 20th sess., ch. 74/p. 100)
23 February 1798
ROCKLAND created from ORANGE. (N.Y. Laws 1798, 21st sess., ch. 16/p. 156)
15 March 1798
CHENANGO created from HERKIMER and TIOGA. ONEIDA created from HERKIMER. (N.Y. Laws 1798, 21st sess., ch. 31/p. 170)
5 April 1798
ULSTER gained from ALBANY, lost to ORANGE. (N.Y. Laws 1798, 21st sess., ch. 93/p. 273)
1 March 1799
ESSEX created from CLINTON. (N.Y. Laws 1798-1799, 22d sess., ch. 24/p. 332)
8 March 1799
CAYUGA created from ONONDAGA. (N.Y. Laws 1798-1799, 22d sess., ch. 26/p. 333)
23 March 1799
COLUMBIA gained small area from DUTCHESS. (N.Y. Laws 1798-1799, 22d sess., ch. 37/p. 347)
21 March 1800
ROCKLAND gained from ORANGE. (N.Y. Laws 1800, 23d sess., ch. 51/p. 493)
25 March 1800
GREENE created from ALBANY and ULSTER. (N.Y. Laws 1800, 23d sess., ch. 59/p. 503)
3 April 1801
All county boundaries were redefined. Changes were: ALBANY gained from SCHOHARIE; CAYUGA exchanged with ONTARIO, lost to STEUBEN; CLINTON gained from HERKIMER, MONTGOMERY, and ONEIDA; DELAWARE gained from ULSTER; GREENE gained from DELAWARE and ULSTER; ONEIDA gained eastern end of Lake Ontario [not mapped]; ESSEX, SARATOGA and WASHINGTON gained from MONTGOMERY. (N.Y. Laws 1801, 24th sess., ch. 123/p. 290)
3 March 1802
ST. LAWRENCE created from CLINTON. (N.Y. Laws 1802, 25th sess., ch. 16/p. 24)
30 March 1802
GENESEE created from ONTARIO; GENESEE not fully organized, attached to ONTARIO for administrative and judicial purposes. (N.Y. Laws 1802, 25th sess., ch. 64/p. 97)
March 1803
GENESEE fully organized, detached from ONTARIO. (N.Y. Laws 1802, 25th sess., ch. 64/p. 97)
24 March 1804
SENECA created from CAYUGA. ONTARIO and STEUBEN gained from CAYUGA. (N.Y. Laws 1804, 27th sess., ch. 31/p. 112)
4 April 1804
ONEIDA gained from CHENANGO. (N.Y. Laws 1804, 27th sess., ch. 50/p. 172)
28 March 1805
JEFFERSON and LEWIS created from ONEIDA. (N.Y. Laws 1804, 28th sess., ch. 51, secs. 1-2/p. 73)
21 March 1806
MADISON created from CHENANGO. (N.Y. Laws 1806, 29th sess., ch. 70, sec. 1/p. 398)
28 March 1806
BROOME created from TIOGA. (N.Y. Laws 1806, 29th sess., ch. 89/p. 431)
7 April 1806
ALLEGANY created from GENESEE. (N.Y. Laws 1806, 29th sess., ch. 162, sec. 1/p. 604)
3 April 1807
All county boundaries running along waterways were redefined to run in the main channels of their streams [no mappable changes]. (N.Y. Laws 1807, 30th sess., ch. 90/p. 104)
12 February 1808
LEWIS gained from JEFFERSON. (N.Y. Laws 1808, 31st sess., ch. 15/p. 254)
11 March 1808
ALLEGANY gained from STEUBEN. (N.Y. Laws 1808, 31st sess., ch. 38/p. 263)
CATTARAUGUS and NIAGARA created from ALLEGANY and GENESEE; CHAUTAUQUA created from GENESEE. CATTARAUGUS and CHAUTAUQUA not fully organized, both attached to NIAGARA for administrative and judicial purposes. GENESEE gained from ALLEGANY. (N.Y. Laws 1808, 31st sess., ch. 40, secs. 1-2/p. 266)
FRANKLIN created from CLINTON. (N.Y. Laws 1808, 31st sess., ch. 43/p. 272)
8 April 1808
CORTLAND created from ONONDAGA. (N.Y. Laws 1808, 31st sess., ch. 194, sec. 1/p. 365)
7 March 1809
SCHENECTADY created from ALBANY. (N.Y. Laws 1808, 32d sess., ch. 65, sec. 1/p. 458)
27 March 1809
SULLIVAN created from ULSTER. (N.Y. Laws 1808, 32d sess., ch. 126, sec. 1/p. 495)
5 April 1810
JEFFERSON gained from LEWIS. (N.Y. Laws 1810, 33d sess., ch. 164/p. 68)
9 February 1811
CHAUTAUQUA fully organized, detached from NIAGARA. (Doty et al, 1:360)
26 May 1812
ULSTER gained from GREENE. (N.Y. Laws 1812, 35th sess., ch. 46/p. 382)
8 June 1812
ULSTER gained small area from DELAWARE. (N.Y. Laws 1812, 35th sess., ch. 88/p. 427)
12 June 1812
PUTNAM created from DUTCHESS. (N.Y. Laws 1812, 35th sess., ch. 143, sec. 1/p. 479)
Legislature authorized CATTARAUGUS to be attached to ALLEGANY, but attachment did not take effect. (N.Y. Laws 1812, 35th sess., ch. 173/p. 517)
12 March 1813
WARREN created from WASHINGTON. (N.Y. Laws 1812, 36th sess., ch. 50/p. 48)
2 April 1813
JEFFERSON gained from LEWIS. (N.Y. Laws 1812, 36th sess., ch. 117/p. 189)
25 February 1814
ONTARIO gained from STEUBEN. (N.Y. Laws 1814, 37th sess., ch. 24/p. 27)
13 April 1814
Eastern half of CATTARAUGUS was detached from NIAGARA, attached to ALLEGANY for administrative and judicial purposes. (N.Y. Laws 1814, 37th sess., ch. 123/p. 146)
15 April 1814
ULSTER gained from GREENE. (N.Y. Laws 1814, 37th sess., ch. 211/p. 275)
14 April 1815
CORTLAND gained from BROOME. (N.Y. Laws 1814, 38th sess., ch. 198/p. 200)
1 March 1816
OSWEGO created from ONEIDA and ONONDAGA. (N.Y. Laws 1816, 39th sess., ch. 22, sec. 1/p. 16)
12 April 1816
HAMILTON created from MONTGOMERY; HAMILTON not fully organized, attached to MONTGOMERY for administrative and judicial purposes. (N.Y. Laws 1816, 39th sess., ch. 120, sec. 1/p. 119)
10 May 1816
HERKIMER gained from OTSEGO. (N.Y. Laws 1816, 39th sess., ch. 222/p. 270)
28 March 1817
CATTARAUGUS fully organized, detached from ALLEGANY and NIAGARA. (N.Y. Laws 1816, 40th sess., ch. 115, sec. 1/p. 107)
31 March 1817
DELAWARE gained from OTSEGO. (N.Y. Laws 1816, 40th sess., ch. 140/p. 146)
7 April 1817
TOMPKINS created from BROOME, CAYUGA, and SENECA. (N.Y. Laws 1816, 40th sess., ch. 189, sec. 1/p. 197)
2 May 1817
HERKIMER gained from MONTGOMERY. (N.Y. Laws 1816, 40th sess., ch. 184/p. 182)
13 April 1819
SENECA gained from TOMPKINS. (N.Y. Laws 1819, 42d sess., ch. 190/p. 239)
23 February 1821
LIVINGSTON created from GENESEE and ONTARIO. (N.Y. Laws 1820, 44th sess., ch. 58, sec. 1/p. 50)
MONROE created from GENESEE and ONTARIO. (N.Y. Laws 1820, 44th sess., ch. 57, sec. 1/p. 46)
2 April 1821
ERIE created from NIAGARA. (N.Y. Laws 1820, 44th sess., ch. 228, sec. 1/p. 220)
21 February 1822
BERKSHIRE (Mass.) lost to FRANKLIN (Mass.) when town of Monroe was created from town of Rowe and non-town area called the Gore. Area within present New York was unchanged. (Mass. Acts 1822, ch. 93, sec. 1/p. 707)
4 March 1822
LIVINGSTON gained from STEUBEN. (N.Y. Laws 1822, 45th sess., ch. 30/p. 31)
22 March 1822
CLINTON and FRANKLIN gained from ESSEX. (N.Y. Laws 1822, 45th sess., ch. 92/p. 94)
TIOGA gained from BROOME. (N.Y. Laws 1822, 45th sess., ch. 75, sec. 1/p. 76)
29 March 1822
RENSSELAER gained small area from WASHINGTON. (N.Y. Laws 1822, 45th sess., ch. 116/p. 116)
12 April 1822
OTSEGO gained from DELAWARE. (N.Y. Laws 1822, 45th sess., ch. 210/p. 206)
17 April 1822
GREENE gained small area from ULSTER. (N.Y. Laws 1822, 45th sess., ch. 243/p. 257)
18 June 1822
Under authority of the Treaty of Ghent (24 December 1814), commissioners from Great Britain and the United States agreed on the detailed course of the U.S.-Canadian boundary from the point where the 45th parallel crosses the St. Lawrence River through Lakes Ontario, Erie, and Huron to the eastern end of Lake Superior, in accordance with the Peace Treaty of 1783, thereby settling details of New York's northwestern boundary [no change]. (Van Zandt, 12-14)
5 February 1823
YATES created from ONTARIO. (N.Y. Laws 1823, 46th sess., ch. 30, sec. 1/p. 21)
22 March 1823
TOMPKINS gained from TIOGA. (N.Y. Laws 1822, 45th sess., ch. 75, sec. 13/p. 78)
11 April 1823
WAYNE created from ONTARIO and SENECA. (N.Y. Laws 1823, 46th sess., ch. 138, sec. 1/p. 158)
23 April 1823
GREENE gained small area from COLUMBIA. (N.Y. Laws 1823, 46th sess., ch. 251/p. 377)
12 April 1824
ERIE gained from NIAGARA. (N.Y. Laws 1824, 47th sess., ch. 242, sec. 6/p. 304)
24 November 1824
Boundaries of KINGS, NEW YORK, and RICHMOND were redefined [no changes]. (N.Y. Laws 1824, 47th sess., ch. 304/p. 358)
4 April 1825
MONROE gained from LIVINGSTON. (N.Y. Laws 1824, 47th sess., ch. 309/p. 361)
15 April 1825
ORLEANS created from GENESEE. (N.Y. Laws 1824, 47th sess., ch. 266, sec. 1/p. 326; N.Y. Laws 1825, 48th sess., ch. 181, secs. 1-2/p. 273)
1 January 1826
YATES gained from STEUBEN. (N.Y. Laws 1824, 47th sess., ch. 171/p. 182)
1 May 1826
GENESEE gained from ORLEANS. (N.Y. Laws 1826, 49th sess., ch. 269/p. 302)
15 April 1828
CAYUGA exchanged small areas with ONONDAGA; SENECA gained from ONTARIO and YATES; TOMPKINS gained from STEUBEN and YATES. (N.Y. Rev. Stat., 3:14-15)
28 June 1834
The United States Congress confirmed the agreement between New Jersey and New York on the course of their over-water boundary from the Hudson River to the Atlantic Ocean [not mapped]. (U.S. Stat., vol. 4, ch. 126 [1834]/pp. 708-711)
3 March 1836
SCHOHARIE gained from GREENE. (N.Y. Laws 1836, 59th sess., ch. 31/p. 33)
29 March 1836
CHEMUNG created from TIOGA. (N.Y. Laws 1836, 59th sess., ch. 77, sec. 1/p. 102)
20 May 1836
MADISON gained from ONEIDA. (N.Y. Laws 1836, 59th sess., ch. 393/p. 588)
1 January 1838
HAMILTON was partially organized, detached from MONTGOMERY. (N.Y. Laws 1837, 60th sess., ch. 238, sec. 1/p. 227)
2 April 1838
BERKSHIRE (Mass.) lost to FRANKLIN (Mass.) when towns of Charlemont and Rowe gained from town of Zoar. Area within present New York was unchanged. (Mass. Acts 1838, ch. 56, sec. 1/p. 344 and ch. 57, sec. 1/p. 345)
18 April 1838
FULTON created from MONTGOMERY. (N.Y. Laws 1838, 61st sess., ch. 332, sec. 1/p. 328)
19 May 1841
WYOMING created from GENESEE. (N.Y. Laws 1841, 64th sess., ch. 196, sec. 1/p. 169)
9 August 1842
Webster-Ashburton Treaty between Great Britain and the United States settled the remaining details of the U.S.-Canadian boundary, including the northern limit of New York [no change]. (Van Zandt, 17-18)
1 April 1846
WYOMING gained from ALLEGANY. (N.Y. Laws 1846, 69th sess., ch. 51/p. 53)
11 May 1846
LIVINGSTON gained from ALLEGANY. (N.Y. Laws 1846, 69th sess., ch. 197, sec. 1/p. 235)
by summer 1847
HAMILTON was fully organized. (Aber and King, 51)
4 May 1853
BERKSHIRE (Mass.) boundary with HAMPDEN (Mass.) was clarified when the line between the towns of Sandisfield and Tolland was clarified [no change]. (Mass. Acts 1853, ch. 293/p. 535)
17 April 1854
SCHUYLER created from CHEMUNG, STEUBEN, and TOMPKINS. (N.Y. Laws 1854, 77th sess., ch. 386, secs. 1-4, 6/pp. 913-915)
11 January 1855
COLUMBIA gained from BERKSHIRE (Mass.) when New York acquired the southwestern corner of Massachusetts (Boston Corner); BERKSHIRE eliminated from New York. (Pratt, 2:223; Van Zandt, 70, 76)
23 March 1857
LIVINGSTON gained from ALLEGANY. (N.Y. Laws 1857, 80th sess., ch. 166/p. 366)
1 March 1860
Boundary between QUEENS and SUFFOLK was redefined [no discernible change]. (N.Y. Laws 1860, 83d sess., ch. 530/pp. 1074-1076)
17 March 1860
Legislature authorized ONTARIO to gain from YATES, but change never took effect. (N.Y. Laws 1860, 83d sess., ch. 76/p. 120)
6 April 1860
HAMILTON gained from FULTON. (N.Y. Laws 1860, 83d sess., ch. 178/p. 298)
1 January 1874
NEW YORK gained from WESTCHESTER. (N.Y. Laws 1873, 96th sess., ch. 613, sec. 1/p. 928)
20 March 1879
Boundary between MADISON and ONEIDA was redefined [no discernible change]. (N.Y. Laws 1879, 102d sess., ch. 91/p. 137)
7 April 1880
WASHINGTON gained from RUTLAND (Vt.) when New York gained a small area west of the village of Fair Haven from Vermont due to a change in the course of the Poultney River [change too small to map]. (U.S. Stat., vol. 21, ch. 49 [1880]/p. 72)
26 February 1881
United States Congress confirmed a redefinition of the boundary between Connecticut and New York over land and through Long Island Sound [no change]. (Van Zandt, 74)
8 June 1881
NEW YORK gained North Brother Island from QUEENS. (N.Y. Laws 1881, 104th sess., ch. 478, sec. 1/p. 649)
11 July 1881
Part of the boundary between KINGS and QUEENS was redefined [no discernible change]. (N.Y. Laws 1881, 104th sess., ch. 624/p. 851)
8 May 1884
NEW YORK gained Rikers Island from QUEENS. (N.Y. Laws 1884, 107th sess., ch. 262/p. 328)
15 June 1886
SUFFOLK gained from QUEENS when town of Huntington gained Lloyd's Neck from town of Oyster Bay. (N.Y. Laws 1886, 109th sess., ch. 667/pp. 956-957)
3 March 1888
SARATOGA gained Havre Island from ALBANY and RENSSELAER [change too small to display on interactive map; shapefile users see small_changes 1888_pt. for location]. (N.Y. Laws 1888, 111th sess., ch. 42/p. 85)
6 June 1895
NEW YORK gained from WESTCHESTER. (N.Y. Laws 1895, 118th sess., ch. 934, sec. 1/p. 1948)
4 May 1897
The Boroughs of New York City were established with the same configurations as counties; they assumed most county functions but did not replace them. (N.Y. Laws 1897, 120th sess., ch. 378, sec. 2/p. 2)
1 January 1899
NASSAU created from QUEENS. (N.Y. Laws 1899, 121st sess., ch. 588, sec. 1/p. 1336)
19 April 1912
BRONX created from NEW YORK. (N.Y. Laws 1912, 135th sess., ch. 548, sec. 1/p. 1352)
23 April 1913
FRANKLIN gained from ST. LAWRENCE. (N.Y. Laws 1913, 136th sess., ch. 385, sec. 1/p. 823)
28 April 1915
KINGS gained small area from QUEENS [change too small to display on interactive map; shapefile users see small_changes 1915_pt. for location]. (N.Y. Laws 1915, 138th sess., ch. 410/p. 1325)
24 May 1915
ESSEX exchanged with HAMILTON. (N.Y. Laws 1915, 138th sess., ch. 718, secs. 1-3/p. 2364)
8 May 1917
Boundary between KINGS and QUEENS was redefined [no discernible change]. (N.Y. Laws 1917, 140th sess., ch. 420/p. 1285)
26 May 1917
BRONX gained small area from WESTCHESTER. (N.Y. Laws 1917, 140th sess., ch. 664, sec. 1/p. 2022)
25 March 1922
LIVINGSTON gained small area from ONTARIO [change too small to display on interactive map; shapefile users see small_changes 1922_pt. for location]. (N.Y. Laws 1922, 145th sess., ch. 258, secs. 1-2/p. 615)
2 April 1931
Boundary between KINGS and QUEENS was redefined [no discernible change]. (N.Y. Laws 1931, 154th sess., ch. 237/p. 617)
20 April 1945
Boundary between NASSAU and QUEENS was redefined [no discernible change]. (N.Y. Laws 1945, 168th sess., ch. 895, secs. 1-3/pp. 2101-2106)
18 April 1946
YATES gained from SCHUYLER and SENECA. (N.Y. Laws 1946, 169th sess., ch. 901/p. 1686)
14 April 1950
Boundary between BRONX and WESTCHESTER was redefined [no discernible change]. (N.Y. Laws 1950, 173d sess., ch. 650/p. 1508)
16 April 1964
BRONX gained South Brother Island from QUEENS. (N.Y. Laws 1964, 187th sess., ch. 578/p. 1606)