The United States Capitol often called the Capitol Building, is the home of the United States Congress, and the seat of the legislative branch of the US. It also houses an important collection of American art, and it is an architectural achievement in its own right. The original building was completed in 1800 and was subsequently expanded, particularly with the addition of the massive dome, and expanded chambers for the bicameral legislature, the House of Representatives in the south wing and the Senate in the north wing. Like the principal buildings of the executive and judicial branches, the Capitol is built in a distinctive neoclassical style and has a white exterior.