Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. The signing of the Residence Act on July 16, 1790, approved the creation of a capital district located along the Potomac River on the country's East Coast. The U.S. Constitution provided for a federal district under the exclusive jurisdiction of the Congress and the District is therefore not a part of any U.S. state.
The states of Maryland and Virginia each donated land to form the federal district, which included the preexisting settlements of Georgetown and Alexandria. Named in honor of George Washington, the City of Washington was founded in 1791 to serve as the new national capital. In 1846, Congress returned the land originally ceded by Virginia and created a single municipal government for the remaining portion of the District in 1871.
Washington, D.C., had an estimated population of 646,449 in 2013, the 23rd most populous place in the United States. Commuters from the surrounding Maryland and Virginia suburbs raise the city's population to more than one million during the workweek. The Washington metropolitan area, of which the District is a part, has a population of 5.8 million, the seventh-largest metropolitan area in the country.