What is the formal anniversary term for America250’s 250th celebration?

The formal anniversary term for America250’s 250th celebration is the United States Semiquincentennial.

“Semiquincentennial” combines roots meaning half of five hundred, or 250. It describes the anniversary of the United States Declaration of Independence, adopted in 1776 and commemorated 250 years later in 2026.

America250 is the public-facing name associated with the national celebration. Other historical or technical names have appeared, including sestercentennial, bisesquicentennial, and quarter millennium, but semiquincentennial is the best-known official term.

The word is less familiar than bicentennial, which describes a 200th anniversary. The United States Bicentennial took place in 1976, exactly two centuries after the Declaration’s adoption.