Washington, D.C., capital of the United States, coextensive (since 1878, when Georgetown became a part of Washington) with the District of Columbia (2000 pop. 572,059), 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. Information from http://www.infoplease.com