1966

The 1966 quarter is the second year of the clad composition and the second consecutive year in which Treasury suspended mintmarks across U.S. coinage. The Mint struck 821,101,500 pieces, well below the 1965 first-clad-year explosion of more than 1.8 billion but still a heavy output by historical standards. The composition is the new outer cladding of 75% copper and 25% nickel bonded to a pure copper core, with the finished blank weighing 5.67 grams and containing no silver. Every 1966 quarter carries no mintmark even though production happened at Philadelphia, Denver, and San Francisco, since Treasury's policy directly responded to the public hoarding behavior of 1964 to 1965 and the rumor mill that specific mints would produce more collectible pieces.

Strike quality on the 1966 runs from average to soft, with the rapid die wear of the high-volume mid-1960s production routinely yielding weak eagle breast feathers and indistinct hair detail above the ear. Authentication priorities focus on the absence of a mintmark and on confirming the clad composition. The weight test confirms 5.67 grams versus a silver coin's 6.25 grams; edge appearance shows the reddish copper-core line characteristic of clad. Counterfeit pieces with added D or S mintmarks have appeared on 1965 through 1967 dates, so any 1966 carrying a mintmark deserves immediate rejection as altered. A documented 1966 Doubled Die Obverse exists with visible doubling on the motto IN GOD WE TRUST and date, recognized by specialists and trading at meaningful premiums when properly attributed. Population reports at PCGS, the Professional Coin Grading Service, show the issue plentiful through MS64, with a clear thinning at MS66 and genuine condition rarity above that mark where the high-output dies yielded few well-struck survivors.

The 1966 is a common date in the modern catalog, set-fillable in circulated grades essentially at face value and obtainable in MS65 without much hunting. Registry-set builders pursue the thin MS67 pool, and roll-hunters continue to search original bank-wrapped 1966 quarters for the documented DDO and for high-end strike examples that the era's bag-mark conditions made scarce. Realistic acquisition is a certified MS65 or MS66 from a major auction, with the upgrade path running into firm resistance at MS67 where strike and surfaces both matter. For the broader story of John Flanagan's design, the 1965 silver-to-clad transition, and the series' production arc, see the Washington Quarter series history.