What name does America250 use for the United States’ 250th anniversary?

America250 uses the term semiquincentennial for the United States’ 250th anniversary.

The word combines Latin-derived parts meaning half and five hundred, producing the sense of a half-millennium anniversary. In ordinary American usage, “America250” is the shorter public-facing name, while “United States Semiquincentennial” is the formal historical term for the 2026 commemoration.

The anniversary marks 250 years from the 1776 adoption of the Declaration of Independence. It follows the United States Bicentennial in 1976, which marked 200 years, and the sesquicentennial in 1926, which marked 150 years. These labels describe anniversaries by the number of years being commemorated.

People sometimes confuse “semiquincentennial” with “quatercentennial.” A quatercentennial marks 400 years, while a semiquincentennial marks 250. The spelling can also vary slightly in informal writing, but “semiquincentennial” is the standard term used for the United States’ 250th anniversary.