The United States’ 250th anniversary is called the Semiquincentennial, commemorated nationwide in 2026.
The word combines “semi,” meaning half, with “quincentennial,” relating to 500 years. Together, the term describes half of a 500th anniversary, or 250 years. “United States Semiquincentennial” is the formal name commonly used for America250 celebrations.
The anniversary marks the 250th anniversary of the Declaration of Independence and the independence resolution adopted in 1776. The main anniversary date is July 4, 2026, exactly 250 years after Congress approved the Declaration.
Other terms sometimes appear in historical writing, including “sestercentennial,” “bisesquicentennial,” and “quarter millennium.” However, Semiquincentennial is the standard official term used by the federal commission and America250 branding. It should not be confused with “bicentennial,” which describes a 200th anniversary and referred to the major U.S. celebrations in 1976.