High Quality Content by WIKIPEDIA articles! 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 United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution. The federal district is therefore not a part of any U.S. state. It was formed from land along the Potomac River donated by the states of Maryland and Virginia; however, the Virginia portion was returned by Congress in 1846.