What was the previous U.S. national anniversary observance before the 2026 Semiquincentennial?

The previous U.S. national anniversary observance before the 2026 Semiquincentennial was the United States Bicentennial.

The Bicentennial took place in 1976 and commemorated the 200th anniversary of the Declaration of Independence. Its major observances included parades, fireworks, historical projects, the American Freedom Train, Operation Sail, and locally organized events throughout the country and abroad.

The sequence of anniversary names reflects the number of years being marked. The 1976 event was a bicentennial, meaning 200 years, while the 2026 event is a semiquincentennial, meaning 250 years. Earlier national observances included the Centennial Exposition in 1876 and the Sesquicentennial Exposition in 1926.

The 2026 celebration therefore continued a long tradition of commemorating the founding era at major milestones. Although the formats and organizations changed, both the 1976 and 2026 observances centered on the Declaration of Independence and July 4.