In America250 terminology, what word names a 250th anniversary?

In America250 terminology, a 250th anniversary is called a semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. It therefore describes half of five centuries, or 250 years. The United States’ semiquincentennial marks the 250th anniversary of the 1776 Declaration of Independence.

Several similar anniversary terms are easy to confuse. A bicentennial is 200 years, a sesquicentennial is 150 years, and a tricentennial is 300 years. “Bisesquicentennial” and “sestercentennial” have also appeared as alternatives, but “semiquincentennial” is the standard term used in the America250 context.

America250 celebrations focus on July 4, 2026, while also recognizing the wider history of the United States before and after independence. The anniversary is part of a sequence that includes the 1976 bicentennial and the 1876 centennial.