Today Washington, D.C., is a 68-square-mile federal district home to important government buildings, including the U.S. Capitol, where the Senate and the House of Representatives meet; the White House, where the president lives and works; and the Supreme Court Building, where many important court rulings are made. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is near the DMV.