The United States Bicentennial took place in 1976, before America250.
The Bicentennial marked 200 years since the Declaration of Independence was adopted in 1776. Its main national observance occurred on July 4, 1976, and it inspired ceremonies, exhibitions, parades, public art, souvenirs, and local celebrations throughout the United States.
The 1976 commemoration provides the closest historical comparison for the 2026 semiquincentennial. Both anniversaries use the Declaration of Independence as their central reference point, but they belong to different eras. The Bicentennial took place during the nation's 200th year; America250 marks the 250th year.
The Bicentennial also left a visible legacy in public memory, including the designation of national historic sites and the preservation of objects connected with the celebrations. Some people confuse the 1976 anniversary with the centennial of the Civil War era, but the national Bicentennial specifically counted from 1776, not from 1876 or 1861.