Kennedy Halves, Proof
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. 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. In 1971, proofs were made in copper-nickel clad, following the elimination of silver from all circulating US coins in 1970.
In 1975 and 1976, 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. A small number of proof bicentennial half dollars were minted in 40% silver. Otherwise, all Kennedy half dollars were minted in copper-nickel clad until 1992, when 90% silver proofs were reintroduced as an option for collectors.
The scarcest proof Kennedy half dollars are those with varieties, such as the 1964 Heavily Accented Hair half dollar. 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. In 2014, the West Point Mint struck a one-year-only gold proof Kennedy half dollar in honor of the 50th anniversary of the beloved coin series. These generally trade for a small but healthy markup over spot prices.