Washington, D.C., formally the District of Columbia and commonly called Washington or D.C., is the capital city of the United States. The city is located on the east bank of the Potomac River, which forms its southwestern border with Virginia, and borders Maryland to its north and east. The city was named for George Washington, a Founding Father, victorious commanding general of the Continental Army in the American Revolutionary War, and the first president of the United States who is sometimes referred to as "Father of his country"; the district is named for Columbia, the female personification of the nation.
Washington, D.C. is at the southern end of the Northeast megalopolis, one of the nation's largest and most influential cultural, political, and economic regions that runs along the coast from Boston in the north to Washington, D.C. in the south and includes New York City, Philadelphia, and Baltimore. As the seat of the U.S. federal government and several international organizations, the city is an important world political capital. It is the eighth-most visited city in the U.S. with over two million visitors as of 2019.
The U.S. constitution provides for a federal district under the exclusive jurisdiction of the U.S. Congress. Washington, D.C. is not a part of any U.S. state and is not one itself. The Residence Act, adopted on July 16, 1790, approved the creation of the capital district along the Potomac River. The city was founded in 1791, and Congress held its first session there in 1800. The city originally had smaller boundaries than it does now and was intended to be separate from the District of Columbia, while still being within it.
In 1801, the territory, formerly part of Maryland and Virginia and including the settlements of Georgetown and Alexandria, was officially recognized as the federal district. In 1846, Congress returned the land originally ceded by Virginia, including the city of Alexandria; in 1871, it created a single municipal government for the remaining portion of the district that only lasted for three years for a variety of reasons, including budgetary constraints.