What term does America's 250th-anniversary observance use for a 250-year milestone?

America’s 250th-anniversary observance is called the Semiquincentennial. The word combines Latin-derived elements meaning half of five hundred, or 250 years.

The term describes the anniversary of the United States Declaration of Independence on July 4, 2026. America250 is the branding used for the national commemoration, while Semiquincentennial is the formal anniversary term.

A common mix-up is “sesquicentennial,” which means a 150th anniversary. “Bicentennial” means 200 years, and “tercentennial” means 300 years. The 2026 observance follows the United States Bicentennial in 1976 and precedes the expected Tricentennial in 2076.