The United States Capitol, often called the Capitol or the Capitol Building, is the seat of the United States Congress, the legislative branch of the federal government. It is located on Capitol Hill at the eastern end of the National Mall in Washington, D.C. Although no longer at the geographic center of the national capital, the U.S. Capitol forms the origin point for the street-numbering system of the district as well as its four quadrants. Like the principal buildings of the executive and judicial branches, the Capitol is built in a neoclassical style and has a white exterior.
Central sections of the present building were completed in 1800, when the 6th U.S. Congress convened there on November 17, 1800, moving the national capital from Philadelphia to Washington, D.C.. The building was partly destroyed in the 1814 Burning of Washington by British forces, then was fully restored within five years. The building was enlarged during the 19th century, by extending the wings for the chambers for the bicameral legislature as more states were admitted to the union, with the House of Representatives housed in the south wing and the Senate housed in the north wing. The massive dome was completed around 1866 just after the American Civil War. The east front portico was extended in 1958. The building's Visitor Center was opened in the early 21st century.
Both its east and west elevations are formally referred to as fronts, although only the east front was intended for the reception of visitors and dignitaries, while the west front is now used for presidential inauguration ceremonies. The building and grounds are overseen by the architect of the Capitol, who also oversees the surrounding Capitol Complex.
Prior to establishing the nation's capital, Washington, D.C., the United States Congress and its predecessors met at Independence Hall and Congress Hall in Philadelphia; Federal Hall in New York City, and five additional locations: York, Pennsylvania; Lancaster, Pennsylvania; the Maryland State House in Annapolis, Maryland; Nassau Hall in Princeton, New Jersey; and Trenton, New Jersey. In September 1774, the First Continental Congress brought together delegates from the colonies in Philadelphia, followed by the Second Continental Congress, which met from May 1775 to March 1781.
After adopting the Articles of Confederation in York, Pennsylvania, the Congress of the Confederation was formed and convened in Philadelphia from March 1781 until June 1783, when a mob of angry soldiers converged upon Independence Hall, demanding payment for their service during the American Revolutionary War. Congress requested that John Dickinson, the Governor of Pennsylvania, call up the militia to defend Congress from attacks by the protesters. In what became known as the Pennsylvania Mutiny of 1783, Dickinson sympathized with the protesters and refused to remove them from Philadelphia. As a result, Congress was forced to flee to Princeton, New Jersey, on June 21, 1783, and met in Annapolis, Maryland, and Trenton, New Jersey, before ending up in New York City.
The U.S. Congress was established upon ratification of the U.S. Constitution and formally began on March 4, 1789. New York City remained home to Congress until July 1790, when the Residence Act was passed to pave the way for a permanent capital. The decision of where to locate the capital was contentious, but Alexander Hamilton helped broker a compromise in which the federal government would take on war debt incurred during the American Revolutionary War, in exchange for support from northern states for locating the capital along the Potomac River. As part of the legislation, Philadelphia was chosen as a temporary capital for ten years (until December 1800), until the nation's capital, Washington, D.C., would be ready.
Pierre L'Enfant was charged with creating the city plan for the new capital city and the major public buildings. The Congress House would be built on Jenkins Hill, now known as Capitol Hill, which L'Enfant described as a "pedestal awaiting a monument." L'Enfant connected Congress House with the President's House via Pennsylvania Avenue with a width set at 160 feet, identical to the narrowest points of the Champs-Élysées in Paris. Westwards was a 400-foot-wide (120 m) garden-lined "grand avenue" containing a public walk (later known as the National Mall) that would travel for about one mile (1.6 km) along the east–west line.
The term "Capitol" (from Latin Capitolium) originally denoted the Capitoline Hill in Rome and the Temple of Jupiter that stood on its summit. The Roman Capitol was sometimes misconceived of as a meeting place for senators, and this led the term to be applied to legislative buildings; the first such building was the Williamsburg Capitol in Virginia. Thomas Jefferson had sat here as a member of the House of Burgesses, and it was he who applied the name "Capitol" to what on L'Enfant's plan had been called the "Congress House". "Capitol" has since become a general term for government buildings, especially in the United States. It is often confused with "capital"; the former, however, denotes a building or complex of buildings, while the latter denotes a city.
L'Enfant secured the lease of quarries at Wigginton Island and along Aquia Creek in Virginia for use in the foundations and outer walls of the Capitol in November 1791. Surveying was under way soon after the Jefferson conference plan for the Capitol was accepted. On September 18, 1793, President Washington, along with eight other Freemasons dressed in masonic regalia, laid the cornerstone, which was made by silversmith Caleb Bentley.
In early 1792, after Pierre L'Enfant was dismissed from the federal city project, Jefferson proposed a design competition to solicit designs for the Capitol and the "President's House", and set a four-month deadline. The prize for the competition was $500 and a lot in the Federal City. At least ten individuals submitted designs for the Capitol; however the drawings were regarded as crude and amateurish, reflecting the level of architectural skill present in the United States at the time.
The most promising of the submissions was by Stephen Hallet, a trained French architect who was a draftsman to Pierre L'Enfant on the city plan. However, Hallet's designs were overly fancy, with too much French influence, and were deemed too costly.
However, the design did incorporate the concept for a "great circular room and dome" which had originated with L'Enfant. John Trumbull was given a tour of "Jenkins Hill" by L'Enfant himself and confirmed this in his autobiography years later.
On January 31, 1793, a late entry by amateur architect William Thornton was submitted, and was met with praise for its "Grandeur, Simplicity, and Beauty" by Washington, along with praise from Jefferson. Thornton was inspired by the east front of the Louvre, as well as the Paris Pantheon for the center portion of the design. Thornton's design was officially approved in a letter dated April 5, 1793, from Washington, and Thornton served as the first architect of the Capitol (and later first superintendent of the U.S. Patent and Trademark Office). In an effort to console Hallet, the commissioners appointed him to review Thornton's plans, develop cost estimates, and serve as superintendent of construction. Hallet proceeded to pick apart and make drastic changes to Thornton's design, which he saw as costly to build and problematic.
In July 1793, Jefferson convened a five-member commission, bringing Hallet and Thornton together, along with James Hoban (winning architect of the "President's Palace") to address problems with and revise Thornton's plan. Hallet suggested changes to the floor plan, which could be fitted within the exterior design by Thornton. The revised plan was accepted, except that Secretary Jefferson and President Washington insisted on an open recess in the center of the East front, which was part of Thornton's original plan. The original design by Thornton was later significantly altered by Benjamin Henry Latrobe, and later Charles Bulfinch. The current cast-iron dome, the House's new southern extension, and the Senate's new northern wing were designed by Thomas Ustick Walter and August Schoenborn in the 1850s, and were completed under the supervision of Edward Clark.