What is the formal name for America250’s 250th-anniversary commemoration?

America250’s 250th-anniversary commemoration is formally called the United States Semiquincentennial.

“Semiquincentennial” describes a 250th anniversary. It literally refers to half of a quincentennial, or half of 500 years. The word is unusual because anniversaries of 100 and 200 years—centennials and bicentennials—are much more familiar.

The event commemorates the 250th anniversary of the United States Declaration of Independence, adopted in 1776. Its central anniversary date is July 4, 2026, exactly 250 years after the declaration’s adoption.

Several alternative terms have appeared, including sestercentennial, bisesquicentennial, and quarter millennium. However, “United States Semiquincentennial” is the standard title used for the national commemoration, while America250 is its prominent public brand.