The previous major United States anniversary celebration before the 2026 Semiquincentennial was the Bicentennial.
The United States Bicentennial took place in 1976 and marked 200 years since the Declaration of Independence. It was celebrated nationwide with parades, exhibitions, fireworks, festivals, public works, and historic-site programs. The American Freedom Train was one of the best-known commemorative projects of that period.
The 2026 Semiquincentennial follows the same anniversary sequence: 1776 to 1976 was 200 years, while 1776 to 2026 is 250 years. A centennial marks 100 years, a sesquicentennial marks 150, a bicentennial marks 200, and a tricentennial marks 300.
“Semiquincentennial” is the precise term for the 250th anniversary, although “America250” is the more accessible branding used by the organizing commission. The 1976 celebration is often called the Bicentennial rather than the Semiquincentennial.