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 located along the Potomac River on the country’s East Coast. 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.