What term describes a 250th anniversary, including America’s 2026 milestone?

Semiquincentennial is the term for a 250th anniversary, including America’s 2026 milestone.

The word combines Latin-derived elements associated with half and five hundred, producing a term that means half of 500 years. It is also commonly used for the 250th anniversary of an event, even though “quarter-millennium” is a more literal description.

America’s semiquincentennial commemorates the 250th anniversary of the 1776 Declaration of Independence. The official observance is therefore tied to the founding declaration rather than to the Constitution, the Revolutionary War’s final treaty, or the first presidential inauguration.

The anniversary vocabulary is easy to mix up. A centennial marks 100 years, a sesquicentennial marks 150 years, and a bicentennial marks 200 years. A semiquincentennial reaches 250 years, making it the precise term for the America250 occasion.