The United States’ 1975–1976 Bicentennial coinage comprised three denominations.
The special circulating coins were a quarter, a half dollar, and a dollar. Each carried the double date 1776–1976, even though production occurred in both 1975 and 1976. The temporary reverse designs replaced the normal designs for those denominations.
The quarter showed a colonial drummer, the half dollar featured Independence Hall, and the dollar depicted the Liberty Bell superimposed on the Moon. The coins were produced in large quantities for circulation as well as in collector versions, including silver issues.
The number three refers to denominations, not the number of individual designs, mint facilities, or years of production. That distinction is useful when comparing the Bicentennial coin program with the broader commemorative coinage associated with America250.