What term names America’s 250th anniversary, commemorated by America250?

America’s 250th anniversary, commemorated by America250, is called the Semiquincentennial.

The word combines “semi,” meaning half, with “quincentennial,” meaning a 500th anniversary. Together, the term describes half of five centuries, or 250 years. The commemoration is also known by less common names, including sestercentennial, bisesquicentennial, and quarter millennium.

The anniversary marks the 250th anniversary of the United States Declaration of Independence. The principal anniversary date is July 4, 2026, because the Declaration was proclaimed on July 4, 1776. America250 is the public-facing name associated with the federal semiquincentennial effort.

A common mix-up is confusing “semiquincentennial” with “sesquicentennial.” A sesquicentennial marks 150 years, while a bicentennial marks 200 years. The next major U.S. anniversary after 2026 will be the tricentennial in 2076.