What is the standard name for the 250th anniversary of the United States, celebrated through America250?

The standard name for the 250th anniversary of the United States is the Semiquincentennial.

The term combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Together, the word describes half of five centuries, or 250 years. It is the formal term used for the 2026 anniversary of the Declaration of Independence.

Other labels have appeared, including “bisesquicentennial,” “sestercentennial,” and “quarter millennium.” These alternatives are understandable, but “United States Semiquincentennial” is the name used for the national observance, while “America250” is its public-facing brand.

The terminology can be confusing because “bicentennial” means 200 years, not 250. The United States held its Bicentennial in 1976, and its Sesquicentennial, or 150th anniversary, was marked in 1926. The next 100-year milestone after 2026 will be the Tricentennial in 2076.