What was the previous major U.S. anniversary before the Semiquincentennial?

The Bicentennial was the previous major U.S. anniversary before the Semiquincentennial.

The United States Bicentennial commemorated the 200th anniversary of the Declaration of Independence and culminated on July 4, 1976. It was a nationwide observance rather than a single ceremony, with parades, exhibitions, public projects, commemorative objects, and events highlighting the American Revolution and the nation’s founding.

The anniversary sequence uses Latin-derived number terms. A centennial marks 100 years, a sesquicentennial marks 150, a bicentennial marks 200, and a semiquincentennial marks 250. That makes the 1976 Bicentennial the immediate predecessor to the 2026 Semiquincentennial.

Earlier national commemorations included the Centennial in 1876 and the Sesquicentennial in 1926. Philadelphia hosted major expositions for both of those anniversaries. The Semiquincentennial is also called America’s 250th anniversary and centers on July 4, 2026. “Tricentennial” is not the previous anniversary: it refers to a future 300th anniversary, scheduled for 2076.