Built in the United States Congress on Capitol Hill in downtown Washington, the designer is William Thornton. Start on September 18, 1793, Washington, the president placed a groundbreaking and cornerstone. After 30 years of construction, the buildings built in 1827. Capitol is 766 inches long, 350 inches wide, a total of 550 rooms. Congress is the highest legislative body composed by the Senate and the House of Representatives. Because the parliament building in a small mound about 30 meters high, it was known as Capitol Hill.