What is the standard name for America’s 250th anniversary celebrated by America250?

America’s 250th anniversary, celebrated by America250, is called the United States Semiquincentennial.

The word semiquincentennial combines “semi,” meaning half, with “quincentennial,” relating to 500 years. In this context, it denotes half of a millennium, or 250 years. The term is used for the national commemoration associated with July 4, 2026.

The anniversary marks 250 years since the Second Continental Congress adopted the Declaration of Independence in 1776. America250 is the public-facing name associated with the congressional commemoration, while “United States Semiquincentennial” is the formal historical name commonly used for the anniversary.

Several other anniversary terms are easy to confuse with it. A bicentennial marks 200 years, and a sesquicentennial marks 150 years. “Quincentennial” alone refers to 500 years, so it does not describe the 2026 milestone. Alternative terms such as “sestercentennial” also appear, but semiquincentennial is the standard name used in the event’s formal title.