District of Columbia 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
30 March 1791
The United States created an unnamed district from land ceded by Maryland and Virginia to be the seat of national government. The district was a square with each corner at a point of the compass (north, east, south, and west) and each side ten miles long. Until 1801 the county jurisdictions of Maryland and Virginia continued in the ceded areas. (Richardson, 1:102; Van Zandt, 90)
27 February 1801
The federal government established a circuit court for the seat of national government, now called the District of Columbia, and created two counties to administer judicial and administrative functions: ALEXANDRIA (now ARLINGTON, Va.) covered the the part of the district west of the Potomac River that had been ceded from FAIRFAX (Va.) in 1791; WASHINGTON (extinct) covered the area east of the Potomac River that had been ceded from MONTGOMERY (Md.) and PRINCE GEORGES (Md.) in 1791. The two counties shared concurrent jurisdiction of the Potomac. FAIRFAX (Va.), MONTGOMERY (Md.) and PRINCE GEORGES (Md.) eliminated from the District of Columbia. (U.S. Stat., vol. 2, ch. 15 [1801]/pp. 103-108)
7 September 1846
The federal government retroceded to Virginia all of the District of Columbia west of the Potomac River, including all of ALEXANDRIA (now ARLINGTON, Va.). ALEXANDRIA eliminated from the District of Columbia. (U.S. Stat., vol. 9, ch. 35 [1846]/pp. 35-37, and appendix 3/p. 1000)
21 February 1871
The federal government reorganized the District of Columbia on the model of a unified territorial government without lower levels of county or municipal government; WASHINGTON (extinct) eliminated, although for a while it persisted informally as a geographic unit. (U.S. Stat., vol. 16, ch. 62 [1871]/pp. 419-429)