Washington, D.C., is the capital city of the United States. "D.C." is an abbreviation for the District of Columbia, the federal district coextensive with the city of Washington. The city is named after George Washington, military leader of the American Revolution and the first President of the United States. Columbia in this context is an early poetic name for the United States, a reference to Christopher Columbus, an early European explorer of the Americas.
The city is commonly referred to as Washington, The District, or simply D.C. In the 19th century, it was called the Federal City or Washington City.
The centers of all three branches of the U.S. federal government are in the District. It also serves as the headquarters for the World Bank, the International Monetary Fund, the Organization of American States, the Inter-American Development Bank, and other national and international institutions including labor unions and professional associations. Washington is the frequent location of political demonstrations and protests, large and small, particularly on the National Mall. Furthermore, Washington is a popular destination for tourists, the site of numerous national landmarks and monuments. It is a major American cultural center, with a number of important and free museums including the world's largest museum complex (the Smithsonian Institution), galleries, universities, cathedrals, performing arts centers and institutions, and native music scenes.
The District of Columbia and the city of Washington are governed by a single municipal government, and for most practical purposes, are considered to be the same entity. This has not always been the case. Until 1871, when Georgetown ceased to be a separate city, there were multiple jurisdictions within the District. Although there is a municipal government and a mayor, Congress has the supreme authority over the city and district, which results in citizens having less self-governance than residents of the states. The District has a non-voting at-large Congressional representative. In FY2004, federal tax collections were $16.9 billion while federal spending in the District was $37.6 billion.
The population of the District of Columbia is about 581,530 persons. The Washington Metropolitan Area is the eighth largest in the United States with more than five million residents, and the Baltimore-Washington Metropolitan Area has a population exceeding eight million. If Washington, D.C., were a state, it would rank last in area behind Rhode Island, 50th in population ahead of Wyoming, first in population density, and 35th in gross state product.