Editor's note: ABC News' Pierre Thomas is reporting, via Twitter, that an alleged Islamic State supporter in Ohio has been arrested over plans to carry out an attack on US Capitol with bombs and guns. We're currently looking for confirmation and details. - Tom
The United States Capitol, atop Capitol Hill at the eastern end of the National Mall in Washington, D.C., is the seat of the United States Congress, the legislative branch of the U.S. federal government, completed in the year 1800. Though not at the geographic center of the Federal District, the Capitol is the origin point at which the District's four quadrants meet, and around which the city was laid out.
Like the principal buildings of the executive and judicial branches, the Capitol is built in a distinctive neoclassical style and has a white exterior. Though both its east and west elevations are formally referred to as fronts, only the east front was intended for the reception of visitors and dignitaries.
In 2014 the appearance of the Capitol dome was altered by the scaffolding erected for the Dome Restoration Project, which is scheduled to be completed by early 2017.