Cameo and deep cameo proof Kennedy half dollars from the 1960s and early 1970s are also scarce and command solid premiums over prices for typical Kennedy half dollars of the era.
The scarcest proof Kennedy half dollars are those with varieties, such as the 1964 Heavily Accented Hair half dollar. Otherwise, all Kennedy half dollars were minted in copper-nickel clad until 1992, when 90% silver proofs were reintroduced as an option for collectors. A small number of proof bicentennial half dollars were minted in 40% silver. In 19, Kennedy half dollars were partially revamped with 1776-1976 dual dating on the obverse and a depiction of Independence Hall on the reverse to celebrate the nation's bicentennial. In 1971, proofs were made in copper-nickel clad, following the elimination of silver from all circulating US coins in 1970. The first proof Kennedy half dollars were minted in a 90% silver composition, though by the time proof coinage had returned to the annual lineup in 1968, the makeup had been modified to a composition of 40% silver and 60% copper. Proof Kennedy half dollars have been issued for the duration of the series, which began in 1964 save for the period lasting from 1965 through 1967 when the United States Mint ceased production of all proof coinage in favor of proof-like collector coins.
