What official term describes the United States’ 250th anniversary, known as America250?

The official term for the United States’ 250th anniversary, known as America250, is the United States Semiquincentennial.

A semiquincentennial marks 250 years, or half of five centuries. The anniversary commemorates the Second Continental Congress’s adoption of the Declaration of Independence in 1776, with the principal anniversary falling on July 4, 2026.

The name follows the pattern of other anniversary terms. A centennial marks 100 years, a sesquicentennial marks 150 years, a bicentennial marks 200 years, and a tricentennial marks 300 years. “Bisesquicentennial,” “sestercentennial,” and “quarter millennium” have also appeared as alternative descriptions, but United States Semiquincentennial is the principal official name used for America250.

The federal United States Semiquincentennial Commission, commonly associated with the America250 initiative, was established in 2016 to help coordinate commemorative programs. The previous major national anniversary was the bicentennial in 1976.