The United States bicentennial coinage was a set of circulating commemorative coins of a quarter, half dollar, and one dollar coin minted in 1975 and 1976. Regardless of date of coining, each coin bears the dual date "1776-1976". No coins of those denominations dated 1975 were issued.
Design
In 1975, the United States Mint began minting all quarter, half dollar and dollar coins with special designs on their reverse, commemorating the 200th anniversary (bicentennial) of the independence of the United States. This special minting was continued until December 31, 1976.
The designs were chosen in an open contest announced by the U.S. Treasury in 1973 with a prize of $5,000 for each design. The reverse of the quarter bore a Colonial drummer, contributed by Jack L. Ahr. That of the half dollar coin bore an image of Independence Hall, Philadelphia submitted by Seth Huntington, and that of the dollar coin showed the Liberty Bell superimposed over an image of the Moon, submitted by Dennis R. Williams.
The Bicentennial dollar coin exists in two major varieties, the result of a die change midway through production. One type has thicker lettering for the motto and denomination; the other is noticeably thinner. Neither variety is particularly scarce.
All of these coins bore the date "1776-1976" on the obverse, making it impossible to tell which were minted in 1975 and which were minted in 1976. In 1977, the original reverse designs and normal dates returned.
Composition
Each denomination was minted on cupronickel-clad planchets composed of 8.33% nickel and 91.67% copper, the standard composition for all circulating U.S. quarters dated 1965 and after, and half-dollars and dollars dated 1971 and after.
As collectors" items, limited numbers of each denomination were also minted in clad (in mint and proof sets) and in 40% silver proof versions, mounted in a cardboard backing encased in transparent polystyrene. The composition of the silver version is identical to that of the Kennedy half dollars minted from 1966 to 1970.
Quantities
Because very large quantities of the circulation-variety commemoratives were minted, the two lower-denomination (the Eisenhower dollar no longer circulates) Bicentennial coins are still often found in everyday commerce and carry no premium over face value.
While most quarters remaining in circulation show wear due to over thirty years of use, half dollars, which circulate little and often remain in bank vaults for years, can be found in better condition.
In all, many millions of the Bicentennial coins, including the collectors" issues mentioned above, remain available; the sheer volume of specimens keeps prices low.
In a 1975 press release, The US Mint indicated that it intended to mint "at least 300 million dollars, 550 million half dollars and 1.6 billion quarters for circulating" in addition to the 45 million 40%-silver coins