Which exposition marked the United States' 150th anniversary in Philadelphia in 1926?

The Sesquicentennial Exposition marked the United States' 150th anniversary in Philadelphia in 1926.

Also known as the Sesqui-Centennial International Exposition, the world's fair commemorated the 150th anniversary of the signing of the Declaration of Independence. It also marked 50 years since Philadelphia's 1876 Centennial Exposition, making the city a recurring center for national anniversary observances.

The fair opened in late May 1926 and operated through November on grounds in South Philadelphia. Its buildings, exhibits, patriotic ceremonies, and entertainment were designed to celebrate American history, industry, science, and culture. Attendance reached about six million people.

The event is often confused with the Centennial Exposition of 1876 or the United States Bicentennial of 1976. “Sesquicentennial” means a 150th anniversary, while “semiquincentennial” refers to a 250th anniversary—the milestone America250 commemorated in 2026.