What is the formal anniversary term for America250, marking 250 years since U.S. independence?

The formal anniversary term for America250 is semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Half of 500 is 250, so a semiquincentennial is a 250th anniversary. The term is used for the United States’ 2026 commemoration of the Declaration of Independence and the nation’s founding era.

America250 is the public-facing branding associated with the celebration, while United States Semiquincentennial is the formal historical name. The anniversary date was July 4, 2026, exactly 250 years after the Second Continental Congress adopted the Declaration in 1776.

The term is sometimes confused with other anniversary words. A bicentennial marks 200 years, a sesquicentennial marks 150 years, and a centennial marks 100 years. “Quasquicentennial” is another 125-year anniversary term, so it does not describe America250.