U.S. Capitol

Capitol, U.S., building in Washington, D.C. that houses the Congress of the United States. The U.S. Senate occupies the north wing of the Capitol, and the U.S. House of Representatives the south.

The Capitol is a brilliant white structure in the classical style. It occupies about 3 1/2 acres of high ground known as Capitol Hill (a term also used for Congress) in the center of Washington. The most striking feature of the building is its great white-painted iron dome, 288 ft (88 m) high and 135 1/2 ft (41 m) in diameter, with a statue representing freedom on the top. William Thornton designed the Capitol in 1792 and construction began in 1793 when President George Washington laid the cornerstone. Disagreements and war repeatedly delayed completion until 1906, when the wings were finished. In the late 1950s, the central portico of the east façade was extended, adding 2 more acres of floor space.