On what date was the cornerstone of the United States Capitol laid under George Washington’s presidency?

The cornerstone of the United States Capitol was laid under George Washington’s presidency on September 18, 1793.

Washington participated in a Masonic ceremony at the construction site in the developing Federal City, later known as Washington, D.C. Joseph Clark, grand master of the Grand Lodge of Maryland, assisted him during the ritual.

Construction foundations had begun earlier that summer. The Capitol was intended to serve as the home of Congress in the permanent national capital, whose establishment followed the Residence Act of 1790.

The ceremony included Masonic regalia, a silver commemorative plaque, and a 15-gun salute representing the states then in the Union. The Capitol would take many years to complete, and the building later underwent major changes and reconstruction.