District of Columbia contains the administrative territorial entity Washington County
Foundation
Prior to the establishment of Washington, D.C., as the nation's capital in 1800, the Second Continental Congress was based in Philadelphia on five separate occasions (May 1775 – July 1776, December 1776 – February 1777, March 1777 – September 1777, July 1778, July 1778 – March 1781, and March 1781 – June 1783). The congressional base was briefly in five other locations: York, Pennsylvania (September 1777), Princeton, New Jersey (1783), Annapolis, Maryland (November 1783 to August 1784), Trenton, New Jersey (November to December 1784), and New York City (January 1785 to March 1789).
On October 6, 1783, after the capital was forced by the Pennsylvania Mutiny of 1783 to relocate to Princeton, New Jersey, Congress resolved to consider a new location for it. The following day, Elbridge Gerry of Massachusetts moved "that buildings for the use of Congress be erected on the banks of the Delaware near Trenton, or of the Potomac, near Georgetown, provided a suitable district can be procured on one of the rivers as aforesaid, for a federal town".In his Federalist No. 43, published January 23, 1788, James Madison argued that the new federal government would need authority over a national capital to provide for its own maintenance and safety. The Pennsylvania Mutiny of 1783 emphasized the need for the national government not to rely on any state for its own security.Article One, Section Eight of the U.S. Constitution permits the establishment of a "District (not exceeding ten miles square) as may, by cession of particular states, and the acceptance of Congress, become the seat of the government of the United States". However, the constitution does not specify a location for the capital. In the Compromise of 1790, Madison, Alexander Hamilton, and Thomas Jefferson agreed that the federal government would pay each state's remaining Revolutionary War debts in exchange for establishing the new national capital in the Southern United States.On July 9, 1790, Congress passed the Residence Act, which approved the creation of a national capital on the Potomac River. The exact location was to be selected by President George Washington, who signed the bill into law on July 16. Formed from land donated by Maryland and Virginia, the initial shape of the federal district was a square measuring 10 miles (16 km) on each side and totaling 100 square miles (259 km2).Two preexisting settlements were included in the territory: the port of Georgetown, Maryland, founded in 1751, and the port city of Alexandria, Virginia, founded in 1749. In  1791–92, a team led by Andrew Ellicott, including Ellicott's brothers Joseph and Benjamin and African-American astronomer Benjamin Banneker, surveyed the borders of the federal district and placed boundary stones at every mile point; many of these stones are still standing.A new federal city was then constructed on the north bank of the Potomac, to the east of Georgetown. On September 9, 1791, the three commissioners overseeing the capital's construction named the city in honor of President Washington. The same day, the federal district was named Columbia, a feminine form of Columbus, which was a poetic name for the United States commonly used at that time. Congress held its first session there on November 17, 1800.Congress passed the District of Columbia Organic Act of 1801, which officially organized the district and placed the entire territory under the exclusive control of the federal government. The area within the district was organized into two counties, the County of Washington to the east and north of the Potomac and the County of Alexandria to the west and south. After the Act's passage, citizens in the district were no longer considered residents of Maryland or Virginia, which ended their representation in Congress.Congress benefited from the city's small size, and Washington was smaller than Columbia, making it easier for the new nation's government to maintain it than if the city was significantly larger.
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