What is the formal name for America’s 250th anniversary, celebrated by America250 in 2026?

America’s 250th anniversary, celebrated by America250 in 2026, is formally 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 anniversary marks the 250th anniversary of the Declaration of Independence and the founding of the United States as an independent nation.

The term is less familiar than “bicentennial,” which describes a 200th anniversary. Other historical labels sometimes appear, including “sestercentennial” and “quarter millennium,” but Semiquincentennial is the name used for the 2026 national commemoration.

America250 is the public-facing name associated with the United States Semiquincentennial Commission and its nationwide programs. The celebration connects the 1776 founding era with the country’s history, achievements, communities, and future.