What is the United States’ 250th anniversary in 2026 called?

The United States’ 250th anniversary in 2026 is called the semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Together, the term describes half of five centuries, or 250 years. The anniversary marks the 250th year since the Declaration of Independence was adopted in 1776.

“Semiquincentennial” is the formal term used for the nationwide commemoration, although alternatives such as “sestercentennial,” “quarter millennium,” and “bisesquicentennial” also appear in reference works. These terms are related, but semiquincentennial is the name most closely associated with the official 2026 celebration.

The United States Semiquincentennial Commission, commonly branded America250, was created by Congress in 2016 to coordinate anniversary initiatives. The milestone follows the 1976 bicentennial and precedes the 2076 tricentennial.