Washington laying the cornerstone of the U.S. Capitol in a photo reproduction of a painting.

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 six Congressional
office buildings and three Library of Congress buildings, all developed
in the 19th and 20th centuries.

Although President George Washington laid the cornerstone of the
U.S. Capitol in 1793, construction of current dome did not begin
until 1856. The dome, which replaced an earlier one made of
copper.

The U.S. Capitol under construction, 1860.

1860 – 1861

The U.S. Capitol as it looks today in Washington, D.C.