Delaware: Consolidated Chronology of State and County Boundaries

Delaware Atlas of Historical County Boundaries

John H. Long, Editor; Peggy Tuck Sinko, Associate Editor and 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. Colonies of the two companies were to be at least 100 miles apart, even in area (including present Delaware) of overlapping grants. (Paullin, pl. 42; Swindler, 10:17-23; Van Zandt, 92)

2 June 1609

King James I granted a new charter to the Virginia Company of London, redefining its jurisdiction along the coast as 200 miles north and south of Point Comfort (c. 37 degrees north latitude), including islands within 100 miles, and expanding its area westward and northwestward to the Pacific Ocean; covered area of present Delaware. (Paullin, pl. 42; Swindler, 10:24-36; Van Zandt, 92)

12 March 1611/1612

King James I granted a new charter to the Virginia Company of London, expanding its jurisdiction to encompass all land between 30 degrees and 41 degrees north latitude (including present Delaware), plus offshore islands within 300 leagues, including Bermuda, and by implication still extending to the Pacific Ocean. (Swindler, 10:37-45; Van Zandt, 92-93)

24 May 1624

The Court of the King's Bench revoked the charter of the Virginia Company of London, and Virginia became a royal colony under direct authority of the King and Privy Council. Virginia still claimed jurisdiction as fixed by earlier charters, including area of present Delaware. (Morton, 1:106)

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)

20 June 1632

King Charles I created Maryland from the earlier range of Virginia territory, granting it as a proprietary colony to Cecil Calvert, Lord Baltimore. Territory included all "hitherto uncultivated" land that "lieth under the Fortieth Degree of North Latitude," and was bounded on the south by the south bank of the Potomac River, a line from the river's mouth across Chesapeake Bay to Watkins Point, and thence a line due east across the Delmarva peninsula to the ocean, on the east by the Atlantic Ocean and Delaware Bay, and on the west by the meridian of the head of the Potomac. The area included all of present Delaware. (Swindler, 4:359)

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)

15 September 1655

The Dutch captured Fort Casimir (now New Castle, Del.), thereby effectively ending Swedish control of the Delaware River region (part also claimed by Maryland) and annexing it, including all of present Delaware, New Jersey, and eastern Pennsylvania, to New Netherland. (McCormick, 13; Munroe, History of Delaware, 26)

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. (Munroe, History of Delaware, 30-31)

22 August 1666

SOMERSET (Md.) created by Maryland from non-county area south of TALBOT (Md.). Area included all land between the Nanticoke River and the Atlantic Ocean (including part of southern Delaware), but Maryland did not try to exercise jurisdiction in the eastern part that is present Delaware. (Archives of Md., 3:553-555)

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, including dependent areas along the Delaware River and Bay that covered present Delaware. (Parry, 10:231)

22 October 1669

Maryland implicitly asserted its claim to the area of present Delaware by creating two counties along the Atlantic coast: DURHAM (Md., extinct) was created north of "Hoar Kill" (now Lewes) from SOMERSET (Md.) and non-county area along the Atlantic coast; and an unnamed county was created in present southern Delaware and Maryland [unnamed county not mapped]. These counties were never operational. DURHAM included territory in present Delaware and Pennsylvania. (Archives of Md., 5:56-57)

19 June 1672

WORCESTER (Md., original, extinct) created by Maryland from DURHAM (Md., extinct) and the unnamed coastal county in present Delaware. DURHAM (Md.) and the unnamed county were eliminated. WORCESTER (Md., original), located in present Delaware and Pennsylvania, never became operational. (Archives of Md., 5:107-110)

12 September 1673

After completing their re-conquest (August 1673) of old New Netherland, including present Delaware and southeastern Pennsylvania, the Dutch created three countylike courts for settlements along the west side of the Delaware River: HOARKILL (later DEALE, now SUSSEX), NEW AMSTEL (now NEW CASTLE), and UPLAND (extinct), which extended into present Pennsylvania. No inland limits were specified. These courts became the original counties in Delaware. Maryland also claimed the same area creating an overlap between WORCESTER (Md., original, extinct) and the three new Dutch courts. (Docs. of N.Y., 12:507-508; George, Nead, and McCamant, 453-454; Reed, 22)

by 6 November 1674

The Dutch returned New York and the Delaware River settlements of HOARKILL (later DEALE, now SUSSEX), NEW AMSTEL (now NEW CASTLE), and UPLAND (extinct) to the Duke of York in accordance with the Treaty of Westminster (9 February 1673/1674). By 6 November 1674 HOARKILL, NEW AMSTEL, and UPLAND 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 was renamed NEW CASTLE. (Docs. of N.Y., 12:515)

22 September 1676

The Duke of York's laws were extended from New York to the Delaware region; HOARKILL (later DEALE, now SUSSEX), NEW CASTEL, and UPLAND (extinct) were formally placed under the Duke of York's laws. (Docs. of N.Y., 12:561-563; Reed, 13)

12 November 1678

In area of present Delaware, claimed by Maryland but controlled by New York, NEW CASTLE gained from UPLAND (extinct). (Armstrong, 119, 198)

21 June 1680

In area of present Delaware, claimed by Maryland bu controlled by New York, ST. JONES (now KENT) created under the authority of the Duke of York from NEW CASTLE and HOARKILL (later DEALE, now SUSSEX); no inland limits specified. (Docs. of N.Y., 12:654, 664, 666-667; Reed, 12)

4 March 1680/1681

King Charles II created Pennsylvania from parts of earlier grants to Connecticut and Virginia, granting it as a proprietary colony to William Penn. Territory to be bounded on the southeast by the arc of a circle, 12 miles in radius and centered in New Castle, Del. This grant implicitly set the 12-mile circle as the northern limit of the Delaware region, covering most of UPLAND (extinct). (Swindler, 8:243)

by 15 June 1681

In area of present Delaware claimed by Maryland but controlled by New York, HOARKILL renamed DEALE (now SUSSEX). (Turner, 54; Reed, 13)

June 1681

UPLAND (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 12 miles north of New Castle to the parallel of 42 degrees north latitude, including area also claimed by Maryland. A southern remant of UPLAND that had extended south of the circular boundary around New Castle was added to NEW CASTLE in 1682. (Armstrong, 196; Swindler, 8:243)

24 August 1682

The Duke of York transferred to William Penn the western Delaware River region (present Delaware), also claimed by Maryland, including DEALE (now SUSSEX), NEW CASTLE, and ST. JONES (now KENT). The northern limit was set by the twelve-mile circular boundary around New Castle, Del. (established 4 March 1680/1681), and the southern at Cape Henlopen, but no limit specified inland from Delaware Bay. NEW CASTLE implicitly gained the southern remnant of UPLAND (extinct) that had extended south of the circular boundary. (Pa. Archives, 2d ser., 5:739-744)

7 December 1682

William Penn annexed the Delaware River region (present Delaware) to Pennsylvania. The three Delaware courts (termed "counties" from this date forward) of DEALE (now SUSSEX), NEW CASTLE, and ST. JONES (now KENT) were continued without change and became part of the area known as the Territories or Lower Counties of Pennsylvania. Maryland did not abandon its claim to the Delaware region but had no control there. (Swindler, 2:191-192)

by 21 December 1682

In area of present Delaware, claimed by Maryland but controlled by Pennsylvania, ST. JONES renamed KENT. (Penn, 2:324)

25 December 1682

In area of present Delaware, claimed by Maryland but controlled by Pennsylvania, DEALE renamed SUSSEX; SUSSEX gained from KENT. (Turner, 82)

13 November 1685

SUSSEX implicitly gained territory immediately north of Maryland, including part of SOMERSET (Md.) when King James II approved the decision of the Committee for Trade and Plantations, which concluded the area of present Delaware belonged to Pennsylvania, not Maryland. The exact boundary line was not settled until 1760. WORCESTER (Md., original, extinct) eliminated, ending its overlap with Delaware counties. (Lunt, 47; Report on the Resurvey, 145; Van Zandt, 81)

28 May 1687

NEW CASTLE gained from KENT. KENT gained from SUSSEX (Scharf, 2:1030)

by 29 November 1704

KENT, NEW CASTLE, and SUSSEX were separated from Pennsylvania when Delaware became a distinct colony. (Penn, 4:309; Rodney, 239)

10 May 1732

Non-County Area 1 created in Delaware when representatives of Maryland and Pennsylvania agreed on the boundary between their two colonies, including the line between Maryland and Delaware. The two sides could not agree on how to implement the agreement, and the line was not settled until 4 July 1760 when the Penns and Lord Baltimore confirmed the first agreement. King George III did not approve the survey until 1769. (Paullin, 84-85, pl. 100; Pa. Archives, ser. 2, 16:449-460)

4 July 1760

The proprietors of Maryland and Pennsylvania and the Lower Counties (now Delaware) agreed on the course of their common boundary. This settled the southern boundary of SUSSEX, although surveying problems prevented final implementation until 1769. (Lunt, 56; Report on the Resurvey, 179; Van Zandt, 81-82)

11 January 1769

King George III approved Charles Mason and Jeremiah Dixon's demarcation of the 1760 boundary between the Lower Counties (now Delaware) and Maryland and the circular line centered on New Castle that divides Delaware and Pennsylvania [no change]. (Report on the Resurvey, 190; Lunt, 58-61)

2 September 1775

Boundaries of KENT, NEW CASTLE, and SUSSEX completed westward to the Maryland line, eliminating Non-County Area 1. SUSSEX gained from KENT. (Del., Laws of the State, vol. 1, ch. 229, sec. 4/pp. 569-570)

4 July 1776

The three Lower Counties, of KENT, NEW CASTLE, and SUSSEX became an independent state. The name Delaware was formally adopted on 20 September 1776. (Declaration of Independence; Swindler, 2:197)

18 February 1841

KENT gained from NEW CASTLE. (Del. Laws 1841, ch. 347/pp. 401-402; Scharf, 2:1030)


A dispute over the Delaware-New Jersey boundary in the Delaware River formally opened when New Jersey sued Delaware in the U.S. Supreme Court (suit dropped in 1917). (Van Zandt, 79)

24 January 1907

Congress approved a 1905 agreement between Delaware and New Jersey that provided for concurrent jurisdiction of disputed waters of the Delaware River and Bay, but did not settle the question of the exact location of the water boundary between the 2 states. (Van Zandt, 80)

30 June 1921

NEW CASTLE exchanged narrow strips of territory with CHESTER (Pa.) when the U.S. Congress ratified the agreement between Delaware and Pennsylvania on the demarcation of their common boundary. NEW CASTLE lost a small sliver of territory along the circular line (known as the Horn) and gained a small triangular area by the northeast corner of Maryland (known as the Wedge) [not mapped]. (Lunt, 59, 61; Van Zandt, 83)

5 February 1934

The U.S. Supreme Court, deciding a suit filed by New Jersey in 1929, settled the boundary between Delaware and New Jersey through the Delaware River and Bay along its present course [not mapped]. (Van Zandt, 80)