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. On July 16, 1790, the Residence Act approved the creation of a capital district as permitted by the U.S. Constitution. The District is under the exclusive jurisdiction of the United States Congress and is therefore not a part of any U.S. state.
The states of Maryland and Virginia each donated land along the Potomac River on the U.S. East Coast to form the federal district; however, Congress returned the Virginia portion in 1846. The City of Washington, located east of the preexisting port of Georgetown, was founded in 1791 to serve as the new national capital. Congress consolidated the whole District under a single municipal government in 1871. The city and the U.S. state of Washington, which is on the country's Pacific coast, were both named in honor of George Washington.
Washington, D.C., had an estimated population of 617,996 in 2011, the 25th most populous place in the United States. Commuters from the surrounding Maryland and Virginia suburbs raise the city's population to over one million during the workweek. The Washington Metropolitan Area, of which the District is a part, has a population of nearly 5.6 million, the seventh-largest metropolitan area in the country.
The centers of all three branches of the federal government of the United States are in the District, including the Congress, President, and Supreme Court. Washington is home to many national monuments and museums, which are primarily situated on or around the National Mall. The city hosts 176 foreign embassies as well as the headquarters of many international organizations, trade unions, non-profit organizations, lobbying groups, and professional associations.
A locally elected mayor and 13-member city council have governed the District since 1973; however, the Congress maintains supreme authority over the city and may overturn local laws. D.C. residents therefore have less self-governance than residents of U.S. states. The District has a non-voting, at-large Congressional delegate, but no senators. The Twenty-third Amendment to the United States Constitution, ratified in 1961, grants the District three electoral votes in presidential elections.