What earlier national anniversary did America's 250th anniversary follow in the United States?

America's 250th anniversary followed the United States Bicentennial.

The Bicentennial was the nationwide series of celebrations held mainly in the mid-1970s to commemorate the 200th anniversary of the Declaration of Independence. Its culminating date was July 4, 1976, exactly 200 years after the Declaration’s adoption.

Planning began in 1966, when Congress established the American Revolution Bicentennial Commission. Later, the American Revolution Bicentennial Administration coordinated a decentralized program involving parades, historical reenactments, exhibitions, fireworks, sporting events, and cultural projects.

The 1976 observance also inspired distinctive material commemorations. The United States Mint issued circulating quarter, half-dollar, and dollar designs bearing the dual date 1776–1976. America250 follows that earlier milestone by marking 250 years rather than 200.