The 1976 anniversary preceding the United States Semiquincentennial was the United States Bicentennial.
A bicentennial commemorates 200 years, so the 1976 event marked two centuries since the Declaration of Independence was adopted in 1776. The celebration included national ceremonies, historical programs, exhibitions, parades, and a major public emphasis on American history and symbols.
America250 follows the same anniversary sequence. The 2026 semiquincentennial marks 250 years, while the 1976 bicentennial marked 200 years. These labels describe elapsed time, not separate founding events. The Declaration itself remains the historical reference point for both anniversaries.
The 1976 commemoration also influenced later preservation and public-history projects. Many landmarks, museums, communities, and educational institutions used the bicentennial to interpret the Revolution and the country’s development. America250 similarly connects a national anniversary with local historical stories, rather than treating July 4 as only a single-day celebration.