What term describes the United States’ 250th anniversary, including the America250 celebration?

The term for the United States’ 250th anniversary, including the America250 celebration, is semiquincentennial.

The word combines Latin-derived number elements: “semi” means half, “quin” refers to five, and “centennial” relates to a hundred-year period. In practical terms, a semiquincentennial marks two and a half centuries, or 250 years.

The United States has used several names for major anniversaries. The 100th anniversary was the centennial, the 150th was the sesquicentennial, and the 200th was the bicentennial. The 250th anniversary is less familiar because it is a rarer milestone.

“America250” is the public-facing name used by the federal commission organizing the commemoration. Other historical alternatives include “sestercentennial” and “quarter millennium,” but semiquincentennial is the formal term most closely associated with the 2026 observance.