Washington, D.C. is the capital of the United States (2000 pop. 572,059), coextensive (since 1878, when Georgetown became a part of Washington) with the District of Columbia , on the Potomac River; inc. 1802. The city is the center of a metropolitan area (1990 pop. 3,923,574) extending into Maryland and Virginia. With the city of Baltimore to its north in Maryland, it forms a consolidated metropolitan area of some 6.7 million people. Washington is the legislative, administrative, and judicial center of the United States but has little industry; its business is government, and hundreds of thousands are so employed in the metropolitan area. The city is also a major tourist attraction and a cultural center.
Transportation facilities include a subway system that connects the city with many suburbs. The main rail and air hubs are Union Station and Ronald Reagan Washington National and Dulles International airports (both in Virginia). Nearby military installations include Fort McNair, Fort Myer, Andrews Air Force Base, and Bolling Air Force Base.
Besides the Capitol and the White House, other important government buildings and places of historic interest include the Senate and House of Representatives office buildings, the Supreme Court Building, the Pentagon (in Virginia), the Federal Bureau of Investigation building, the Library of Congress, the National Archives Building, Constitution Hall, the Ronald Reagan Building, The Watergate apartment complex, the State Department ( “Foggy Bottom” ), and the headquarters of the World Bank.
*Information from Columbia Encyclopedia, Sixth Edition