On July 9, 1790, Congress passed the Residence Act, which approved the creation of a national capital on the Potomac River.
Named in honor of President George Washington, the City of Washington was founded in 1791 to serve as the new national capital.
In 1846, Congress returned the land originally ceded by Virginia; in 1871, it created a single municipal government for the remaining portion of the District.
Formed from land donated by the states of Maryland and Virginia, the initial shape of the federal district was a square measuring 10 miles (16 km) on each side, totaling 100 square miles (259 km During 1791–92, Andrew Ellicott and several assistants, including a free African American astronomer named Benjamin Banneker, surveyed the borders of the federal district and placed boundary stones at every mile point.
A new federal city was then constructed on the north bank of the Potomac, to the east of Georgetown.
However, the Constitution does not specify a location for the capital.
In what is now known as the Compromise of 1790, Madison, Alexander Hamilton, and Thomas Jefferson came to an agreement that the federal government would pay each state's remaining Revolutionary War debts in exchange for establishing the new national capital in the Southern United States.
The city of Alexandria was a major market in the American slave trade, and pro-slavery residents feared that abolitionists in Congress would end slavery in the District, further depressing the economy.
Alexandria's citizens petitioned Virginia to take back the land it had donated to form the District, through a process known as retrocession.
The city's first motorized streetcars began service in 1888 and generated growth in areas of the District beyond the City of Washington's original boundaries.
Washington's urban plan was expanded throughout the District in the following decades.
Washington had an estimated population of 693,972 as of July 2017. Washington is home to many national monuments and museums, which are primarily situated on or around the National Mall.