United States Bicentennial quarters, half dollars, and dollars bear the dual date 1776–1976.
The paired dates replaced the single-date format temporarily to connect the coins' production with the 200th anniversary of American independence. The Mint struck the special pieces in both 1975 and 1976, but all three denominations displayed 1776–1976 rather than a 1975 date.
Each denomination received a special reverse through a nationwide design competition. The quarter showed a Colonial drummer, the half dollar showed Independence Hall, and the dollar paired the Liberty Bell with the Moon. The ordinary obverse portraits remained George Washington, John F. Kennedy, and Dwight D. Eisenhower.
These were circulating commemorative coins rather than medals reserved only for collectors. Copper-nickel versions entered everyday commerce, while silver-clad versions were also produced for collectors. Their large mintages are why examples remain common.