The capitol is located at the eastern end of the National Mall on a plateau, 88 feet above the Potomac River in Washington D.C., United States. The United States Capitol serves as the seat of government for the United States Congress, and the legislative branch of the U.S. federal government.
The neoclassical dome of the United States Capitol building has come to symbolize democracy for many people. America's governing, the Senate and the House of Representatives have gathered here for almost two centuries. The Capitol's interior reflects the Victorian style of its day. It was among the earliest buildings to have elevators, heaters, and combination gas and steam lights. Classical pilasters and oak paneling are used throughout the building.
With 540 rooms divided among five floors, the Capitol is one of the oldest and biggest building of the United States. The ground floor is allocated to congressional offices. The second floor holds the chambers of the House of Representatives in the south wing and the Senate in the north wing. Under the dome in the center of the Capitol Building is the Rotunda, a circular space that serves as a gallery of paintings and sculpture of American historical figures and events.
The third floor allows access to the galleries from which visitors may watch the proceedings of the House of Representatives and the Senate when Congress is in session. Additional offices and machinery rooms occupy the fourth floor and the basement.
The Capitol also has its own private subway and underground tunnels connecting the main building with the Congressional Office Buildings. The principal areas of the Capitol are: Brumidi Corridors, The Senate Chamber, The dais in the Old Senate Chamber, The Old Supreme Court Chamber, The Rotunda, The House Chamber, National Statuary Hall, Cox Corridor and The Cryp (a chamber beneath the main floor).
In the spring of 1792, Thomas Jefferson proposed a competition to solicit designs of the Capitol and the President's House, with four-month deadline. Construction on the Washington United States Capitol began in 1793 when George Washington laid the the first stone. The majority of the construction work was actually done by African Americans, both free and slaves.
Thornton's design was officially approved in a letter, dated April 5, 1793, from George Washington, but construction preceded slowly under a succession of architects, including Stephen Hallet (1793), George Hadfield (1795-98) and James Hoban (1798-1802) architect of the White House.
The Senate wing was completed in 1800, the House of Representatives wing was completed in 1807, and the House wing was completed in 1811. Though the building was incomplete, the Capitol held its first session of United States Congress on November 17, 1800.
Not long after the completion of both wings, the Capitol was partially burned by the British in August 1814, during the War of 1812. Reconstruction began in 1815 and was completed by 1819. Construction continued through to 1826, with the addition of the center Rotunda area and the first dome of the Capitol.
The building was later expanded in 1850 and a new dome replaced the older and smaller one. When the dome of the Capitol was finally completed, it was significantly larger than the original (more than 3 times in the height), and its massive visual weight overpowered the proportions of the columns of the East Portic. The East Front of the Capitol building was rebuilt in 1904, following a design of the architects Carrere and Hastings, who also designed the Senate and House office buildings. A marble duplicate of the sandstone East Front was built during 1958-1962.
In 1969, guards are posted at the capitol for the first time. At 11 September of 2001 the Capitol is closed to the public when terrorists attack the Pentagon. And 8 December, 2001, tours of the U.S. Capitol have resumed.
The Capitol is open to the public for guided tours only. Tours are conducted from 9:00 a.m. to 4:30 p.m., of Monday to Saturday, excepting in Christmas and Thanksgiving day.