What name is given to the United States’ 250th anniversary celebrated by America250?

The United States’ 250th anniversary celebrated by America250 is called the Semiquincentennial.

The word describes half of a quincentennial: “semi” means half, while “quincentennial” refers to a 500th anniversary. The result is a name for a 250th anniversary. Because the term is uncommon, the celebration is more often promoted simply as America250 or the 250th anniversary of the United States.

Several alternative names appear in historical and popular usage. Bisesquicentennial combines Latin-derived parts meaning twice 100 plus 50, while sestercentennial and quarter-millennium are other descriptive options. None is as closely associated with the official 2026 observance as semiquincentennial.

The anniversary commemorates the 1776 adoption of the Declaration of Independence. It is therefore tied to the nation’s Independence Day tradition rather than to the later ratification of the Constitution in 1788.