What formal name describes the United States’ 250th anniversary celebrated by America250?

The formal name for the United States’ 250th anniversary celebrated by America250 is the United States Semiquincentennial.

The word “semiquincentennial” combines Latin-derived parts meaning half of 500, or 250. It is less familiar than “bicentennial,” the term used for the 200th anniversary in 1976. Other names sometimes associated with a 250th anniversary include “sestercentennial,” “bisesquicentennial,” and “quarter millennium,” but America250 materials use “United States Semiquincentennial.”

The observance commemorates the 250th anniversary of American independence and centers on July 4, 2026. The event is also commonly described in everyday language as the United States’ 250th birthday or the 250th anniversary of the Declaration of Independence.

The name distinguishes the 2026 celebration from earlier national anniversaries. The United States Centennial took place in 1876, the Sesquicentennial in 1926, and the Bicentennial in 1976. The next corresponding 300th anniversary will be the Tricentennial in 2076.