What is the official name of America250’s 250th-anniversary observance?

The official name of America250’s 250th-anniversary observance is the United States Semiquincentennial.

“Semiquincentennial” combines Latin-derived parts meaning half of 500, or 250. It describes the anniversary of the United States Declaration of Independence and the national celebrations planned around July 4, 2026.

The event is also sometimes described with less common alternatives, including “bisesquicentennial,” “sestercentennial,” and “quarter millennium.” Those terms refer to the same broad milestone, but “United States Semiquincentennial” is the standard title used for the national observance.

The name distinguishes this anniversary from the Bicentennial of 1976, which marked the 200th anniversary, and from the future Tricentennial in 2076, which will mark 300 years. America250 is the public-facing name associated with the organizing effort.