What term names the United States’ 250th anniversary, also branded as America250?

The term that names the United States’ 250th anniversary, also branded as America250, is semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Together, the parts describe half of five hundred years, or 250 years. The term follows the familiar pattern of centennial for 100 years, bicentennial for 200, and tricentennial for 300.

The anniversary also has less common names, including bisesquicentennial, sestercentennial, and quarter millennium. America250 is the simpler public-facing brand used for the national commemoration and its programs.

The word can cause confusion because “semiquincentennial” is not as familiar in everyday English as “bicentennial.” The 1976 celebration was the United States Bicentennial, while the 2026 celebration is the Semiquincentennial. Both observances commemorate the Declaration of Independence, but they are separated by 50 years.