US Proof Set

About US Proof Set

Sets of proof coins sold by the US Mint. Proof coins are struck twice on polished blanks with polished dies, creating a mirror like field and frosted design. The first official proof set was sold in 1936. Proof sets were not sold from 1943 to 1949 due to wartime priorities. From 1968, proofs were struck at the San Francisco mint with an S mint mark. Over 2 million proof sets are sold annually. The 1955 proof set is the key date due to low mintage.