The United States Capitol: An Overview of the Building and Its Function

The United States Capitol in Washington, D.C., is among the most architecturally impressive and symbolically important buildings in the world. It has housed the meeting chambers of the Senate and the House of Representatives for almost two centuries. Begun in 1793, the Capitol has been built, burnt, rebuilt, extended, and restored; today, it stands as a monument not only to its builders but also to the American people and their government.
As the focal point of the government's Legislative Branch, the Capitol is the centerpiece of the Capitol Complex, which includes the six principal Congressional office buildings and three Library of Congress buildings constructed on Capitol Hill in the 19th and 20th centuries. In addition to its active use by Congress, the Capitol is a museum of American art and history. Each year, it is visited by an estimated 3-5 million people from around the world. A fine example of 19th-century neoclassical architecture, the Capitol combines function with aesthetics. Its designs derived from ancient Greece and Rome evoke the ideals that guided the nation's founders as they framed their new republic. As the building was expanded from its original design, harmony with the existing portions was carefully maintained.
Today, the Capitol covers a ground area of 175,170 square feet, or about 4 acres, and has a floor area of approximately 16-1/2 acres. Its length, from north to south, is 751 feet 4 inches; its greatest width, including approaches, is 350 feet. Its height above the base line on the east front to the top of the Statue of Freedom is 288 feet; from the basement floor to the top of the dome is an ascent of 365 steps. The building contains approximately 540 rooms and has 658 windows (108 in the dome alone) and approximately 850 doorways.
The building is divided into five levels. The first, or ground, floor is occupied chiefly by committee rooms and the spaces allocated to various congressional officers. The areas accessible to visitors on this level include the Hall of Columns, the Brumidi Corridors, the restored Old Supreme Court Chamber, and the Crypt beneath the Rotunda, where historical exhibits are presented.
The second floor holds the Chambers of the House of Representatives (in the south wing) and the Senate (in the north wing) as well as the offices of the congressional leadership. This floor also contains three major public areas. In the center under the dome is the Rotunda, a circular ceremonial space that also serves as a gallery of paintings and sculpture depicting significant people and events in the nation's history. The Rotunda is 96 feet in diameter and rises 180 feet 3 inches to the canopy. The semicircular chamber south of the Rotunda served as the Hall of the House until 1857; now designated National Statuary Hall, it houses part of the Capitol's collection of statues donated by the states in commemoration of notable citizens. The Old Senate Chamber northeast of the Rotunda, which was used by the Senate until 1859, has been returned to its mid-19th-century appearance.
The third floor allows access to the galleries from which visitors to the Capitol may watch the proceedings of the House and the Senate when Congress is in session. The rest of this floor is occupied by offices, committee rooms, and press galleries.
The fourth floor and the basement/terrace level of the Capitol are occupied by offices, machinery rooms, workshops, and other support areas.