Walking Liberty half dollars were only struck in proof for seven years, 1936 to 1942. World War Two was the reason for the hiatus in the striking of proofs of any denomination. The proofs were popular with collectors and each year from 1936 to1942 saw more proofs struck than the previous year. The 1942 is understandably the highest mintage and most common of the proof Walking Liberty half dollars. There are a substantial number of Superb Gems known, along with a very small number of Cameos.