What is the formal anniversary term for America250, the 250th anniversary of U.S. independence?

The formal anniversary term for America250, the 250th anniversary of U.S. independence, is semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Together, the term describes half of 500 years, or 250 years. “Sestercentennial” and “bisesquicentennial” are also recorded alternatives, but semiquincentennial is the principal formal term used for the national commemoration.

America250 is a shorter public-facing name for the United States Semiquincentennial. The commemoration centers on the 250th anniversary of the Declaration of Independence, adopted by the Second Continental Congress in 1776.

The name is sometimes confused with “bicentennial,” which means 200 years, or “sesquicentennial,” which means 150 years. “Tricentennial” means 300 years and therefore refers to a future anniversary.