The United States Semiquincentennial marks 250 years of U.S. history in 2026.
The anniversary counts from the adoption of the Declaration of Independence on July 4, 1776. The word semiquincentennial means a 250th anniversary: “semi” means half, and “quincentennial” refers to 500 years.
America250 is the national effort associated with this milestone. The commemoration focuses on the country’s founding, its historical development, and the contributions of people and communities across the United States.
A common mix-up is calling the anniversary a bicentennial. Bicentennial means 200 years, which describes the 1976 celebration. The 2026 anniversary is therefore a semiquincentennial, although several alternative terms have also appeared in historical and popular usage.