On November 17, 1800, Congress held its first session in Washington, D.C. in an incomplete Capitol Building. From the article:
"The US Capitol Building
The United States Capitol is among the most symbolically important and architecturally impressive buildings in the nation. It has housed the meeting chambers of the House of Representatives and the Senate for two centuries. The Capitol, which was started in 1793, has been through many construction phases. It stands today as a monument to the American people and their government.
An example of 19th-century neoclassical architecture, the Capitol evokes the ideals that guided the Founding Fathers as they developed the new republic. Pierre Charles L'Enfant was expected to design the Capitol, but his dismissal in 1792 due to his refusal to cooperate with the Commissioners of the Federal Buildings, resulted in other plans. A competition was suggested by Secretary of State Thomas Jefferson and President George Washington that would award $500 and a city lot to whomever produced the winning plan by mid-July. None of the 17 plans submitted were satisfactory. In October, a letter arrived from Dr. William Thornton, a Scottish-trained physician living in the British West Indies, requesting an opportunity to submit his plan after the competition was closed. The Commissioners granted his request and President Washington commended the plan that was soon accepted by the Commissioners.
The cornerstone was laid by President Washington on September 18, 1793. Because of Thornton's inexperience, the initial work progressed under the direction of three architects in succession. Stephen H. Hallet and George Hadfield were dismissed because of inappropriate design changes they tried to impose; James Hoban, winner of the competition for the President's House, was placed in charge and saw to the completion of the north wing for the first session of Congress on November 17, 1800. In 1803, construction resumed under Benjamin Henry Latrobe who completed the south and north wings. By 1813, Latrobe, with his job done, departed with the wings connected by a temporary wooden passageway.
On August 24, 1814, British troops set fire to the building during the War of 1812. A rainstorm prevented its complete destruction and Latrobe returned to Washington in 1815 to make repairs. He took this opportunity to make changes to the building's interior design and to introduce new materials, such as marble. Latrobe, however, resigned his post in November of 1817 because of construction delays and increasing costs. Charles Bulfinch, a Boston architect, was appointed Latrobe's successor in January of 1818. Continuing the restoration, he was able to make the chambers of the Senate and House, as well as the Supreme Court, ready for use by 1819. Bulfinch redesigned the central section, making the dome that topped the section higher. Bulfinch spent his last couple of years on the Capitol's landscaping and decoration until his position was terminated in 1829.
By 1850, the Capitol could no longer accommodate the increasing numbers of senators and representatives. Another competition was held offering $500 for the best plan to extend the Capitol. Unable to decide between the plans, Congress divided the money between five architects and Thomas U. Walter was chosen to complete the task. Walter supervised the construction of the extensions, making sure they were compatible with the existing style of the building, but using marble for the exterior instead of sandstone, which deteriorates quickly. As the wings progressed, they more than doubled the length of the Capitol making the dome too small for the new proportions. In 1856, the old dome was removed and work began on a replacement with a new, fireproof cast-iron dome. Construction was suspended in 1861 so that the Capitol could be used as a military barracks, hospital and bakery for the Civil War. However, in 1862, construction resumed, because Lincoln believed that the Capitol must go on, just as the Union must go on.
The work on the dome and extensions was completed in 1868 under Edward Clark, who had served as Walter's assistant until his resignation in 1865. Clark held the post of Architect of the Capitol until his death in 1902. Considerable modernization occurred during his tenure, as well as the construction of the marble terraces on the north, west, and south sides of the Capitol. The terraces were constructed as part of the grounds plan devised by landscape architect, Frederick Law Olmsted. After a fire in November 1898, the need for fireproofing became evident. Elliot Woods, Clark's successor, saw to the reconstruction and fireproofing of the damaged wing.
The 20th century has seen even further changes for the Capitol. Under the direction of J. George Stewart, the appointed Architect of the Capitol, the East front extension added 102 more rooms from 1959 to 1960. The stonework was also changed from sandstone to Georgia marble during the process. After a public protest at further plans to expand in the 1970s, the plans were dismissed and the vote went to restore, rather than enlarge, the West Front. Since then, primary emphasis has been on strengthening, renovating and preserving the building.
Today, the Capitol covers a ground area of 175,170 square feet and has a floor area of about 16.5 acres. In addition to its use by Congress, the Capitol is a museum of American art and history. It stands as a focal point of the government's legislative branch and as a centerpiece of Capitol Hill and the National Mall."