What anniversary did the United States commemorate with special coins in 1926?

The United States commemorated its sesquicentennial with special coins in 1926.

A sesquicentennial marks 150 years, so the 1926 observance commemorated 150 years since American independence in 1776. The coin issue included a commemorative half dollar and a quarter eagle, a gold $2.50 piece, struck at the Philadelphia Mint.

The 1926 half dollar is historically notable because it depicted George Washington and Calvin Coolidge on the obverse. Washington was the first United States president, while Coolidge was the sitting president in 1926. Independence Hall appeared on the reverse.

The terminology distinguishes this event from the 1976 bicentennial and the 2026 semiquincentennial. The three milestones represent 150, 200 and 250 years respectively, all measured from the 1776 independence era.