The United States Capitol Dome, symbol of American democracy and world-renowned architectural icon, was constructed of cast iron more than 150 years ago. The Architect of the Capitol recently completed a multi-year project to completely restore the Dome for the first time since 1959-1960.
The project consisted of repairing more than 1,000 cracks to make the Dome watertight and included the restoration and replacement of cast iron and ornamentation. The exterior paint was removed and new layers were applied to protect the dome from corrosion and effects from the elements. The project required scaffolding around the exterior of the Dome, as well as in the Rotunda.