What is the formal name for America's 250th anniversary, known as America250?

America’s 250th anniversary, known as America250, is formally called the United States Semiquincentennial.

The term “semiquincentennial” combines Latin- and Greek-derived elements meaning half of five hundred, or 250. It describes the anniversary of the United States Declaration of Independence and the national observances planned for 2026.

The event is also known by less common names, including sestercentennial, quarter millennium, and bisesquicentennial. “Bicentennial” refers to the 200th anniversary celebrated in 1976, so it is not the correct term for America’s 250th anniversary.

Congress established the United States Semiquincentennial Commission, commonly branded America250, in 2016. Its work connects the 2026 observance with earlier national anniversaries, including the 1876 centennial and 1976 bicentennial.