The first time the Capitol was breached was on August 24, 1814, when British forces entered Washington and burned parts of the city and Capitol. No breach would occur again until the events of January 6th, 2021. Within a year of the first breach and partial burning, the Capitol was being reconstructed, led by two military engineers (George Bomford and Joseph Gardner Swift). During reconstruction of the building, Congress continued to meet but in another building called the Old Brick Capitol that was demolished in 1929. The Capitol was reused for its legislative purpose continuously since 1819. In 1850, the building was significantly expanded to include the new House and Senate wings. The original dome was replaced with a new cast-iron dome that was much larger than the original low, timber-framed design. Thomas U. Walter designed the dome to be 100 feet, with inspiration come from Les Invalides in Paris. A significant part of the construction in the 1850s was carried out slave labor. The Statue of Freedom was placed on top of the dome in 1863, with the dome completed that year. The rotunda is perhaps the oldest and most distinct feature inside the building, which still encompases the 1800 original smaller center. The grounds around the Capitol were extensively redesigned using Fredrick Olmstead's designs between 1874 to 1892. He also recommended new terrace extensions to the north, west, and south sides of the Capitol that have since been completed. New additions occurred to the East Front of the Capitol in 1904, as the large dome and its weight put extra strain on the building. In 1958, the East Portico was extended. Corinthian columns from the original building were also replaced as part of this larger project, with the original columns now used as part of a large display in the National Arboretum. Since 1960, the Captiol has been declared as an official National Historical Landmark in the United States. In 1993, on September 18, 1993, the Capitol's bicentennial was celebrated by re-enacting the masonic ceremony conducted by Washington and others, with Senator Strom Thurmond, a Freemason, leading the ceremony. Until 1981, the East Front of the Capitol was used for Presidential inauguration; the West Front has been used since 1981 for this event.
On December 2, 2008, the United States Capitol Visitor Center opened to the public, the same date the dome finished in 1863, with the building dedicated to tell the history of the site and act as a starting point for tours of the Capitol. The center was built underground on the east side of the Capitol in order to keep the main view of the Capitol Building and Grounds clear of obstruction, with the building itself being about 580,000 square feet. Over the last decade in 2012-2016, extensive restoration has taken place on the building. Roughly $61 million had been appropriated for external renovation, while over $20 million had already been spent on work around the dome. From 2014-2016, extensive scaffolding covered the dome. The work was also pushed quickly so that the 2017 inauguration of President would not have the scaffolding as part of the view. The work was finished just prior to the 2016 election in September of that year . On January 6th, 2021 the capitol was breached for the second time in its history, with four rioters and one police officer killed in the resulting melee.