What earlier U.S. anniversary celebration took place in 1976, before America250?

The earlier U.S. anniversary celebration held in 1976 was the United States Bicentennial.

The Bicentennial marked 200 years since the Declaration of Independence was adopted in 1776. Its principal national observance took place on July 4, 1976, exactly two centuries after the 1776 milestone now commemorated by America250.

The 1976 celebration included exhibitions, parades, festivals and local projects across the country. The sailing ship USS Constitution also participated in a major national ceremonial voyage, and communities used the anniversary to highlight local history as well as national events.

The terms distinguish anniversary intervals: centennial means 100 years, sesquicentennial means 150, bicentennial means 200, and semiquincentennial means 250. America250 therefore follows the Bicentennial by fifty years.