What is the capital of the United States?

The capital of the United States is Washington, District of Columbia, a federal district located on the Potomac River between Virginia and Maryland that has served as the seat of the federal government since 1800. The Constitution authorized Congress in Article I, Section 8 to establish a federal district not exceeding ten miles square as the seat of government, separate from any state. The Residence Act of July 16, 1790, a compromise between Thomas Jefferson, James Madison, and Alexander Hamilton, located the capital on the Potomac River and gave President George Washington discretion to select the exact site.

Maryland and Virginia each ceded land to form a 100 square mile diamond shaped district. Washington selected the precise location and hired French-born engineer Pierre Charles L'Enfant to design the city in 1791. L'Enfant's plan featured broad diagonal avenues, public squares, and a grand central mall connecting the Capitol to the Potomac. Andrew Ellicott completed the survey with the assistance of Benjamin Banneker, a free Black mathematician and astronomer.

Construction proceeded slowly. The cornerstone of the U.S. Capitol was laid on September 18, 1793. The White House cornerstone was laid on October 13, 1792. The federal government moved from Philadelphia to Washington in 1800, and President John Adams became the first occupant of the unfinished White House on November 1, 1800. Congress first met in the unfinished Capitol on November 17, 1800. The British burned the White House, the Capitol, and other public buildings during the War of 1812 on August 24, 1814, but the city was rebuilt.

Major construction milestones included completion of the Capitol dome in 1866, the Washington Monument in 1884, the Lincoln Memorial in 1922, and the Jefferson Memorial in 1943. Virginia's portion of the original district was retroceded by Congress in 1846 (now Arlington and parts of Alexandria), reducing Washington to its current 68 square miles.

Washington has a unique constitutional status. Residents lacked the right to vote in presidential elections until the Twenty-Third Amendment ratified March 29, 1961. The District has no voting representation in Congress, only a non-voting delegate in the House. The Home Rule Act of December 24, 1973 restored an elected mayor and council, but Congress retains plenary authority. The District's population is about 700,000 (more than Wyoming or Vermont), and statehood for the District has been a recurring political question.

The city houses all three branches of the federal government: the White House at 1600 Pennsylvania Avenue, the U.S. Capitol where Congress meets, and the Supreme Court Building completed in 1935. It also contains the Smithsonian Institution museums, the Library of Congress, the National Archives, dozens of foreign embassies, and many monuments and memorials.