Washington, D.C., formally referred to as the District of Columbia and commonly referred to as “Washington” or simply “D.C.”, is the capital of the United States. The U.S. Constitution provided for a federal district under the jurisdiction of the Congress, meaning that the District is not a part of any U.S. state. Washington, D.C., had a 2013 approximate population of just over 650,000, making it the 23rd most populated city in the United States.

Commuters from the surrounding Virgina and Maryland and Virginia suburbs raise the city’s population to more than one million during the working week. The centers of all three branches of the federal government of the United States are in the District, including the Supreme Court, Congress, and the President. Washington is home to many national museums and monuments. The city is host to more than 150 foreign embassies, and is also the headquarters of many trade unions, international organizations, and professional associations.