On September 18, 1793, George Washington lays the cornerstone to the United States Capitol building, the home of the legislative branch of American government. The building would take nearly a century to complete, as architects came and went, the British set fire to it, and it was called into use during the Civil War. Today, the Capitol building, with its famous cast-iron dome and important collection of American art, is part of the Capitol Complex, which includes five Congressional office buildings and three Library of Congress buildings, all developed in the 19th and 20th centuries.
As a young nation, the United States had no permanent capital, and Congress met in eight different cities, including Baltimore, New York City and Philadelphia, before 1791. In 1790, Congress passed the Residence Act, which gave President Washington the power to select a permanent home for the federal government. The following year, he chose what would become the District of Columbia from land provided by Maryland and Virginia.