In the 1960s, coin collecting was a very popular hobby. Collectors searched near and far to fill their collection with complete date sets and silver coins. The mass collecting led to a coin shortage. In an attempt to alleviate the nationwide issue, mint marks were not used from 1965-1967.
The above photo features Superintendent of the Denver Mint, Mrs. Marian Rossmiller, and former ANA president Arthur Sipe standing next to the press used to strike the 1968-D half dollars. Also in attendance was the Denver mayor, Tom Currigan; Lee Martin of COINage magazine; the director of the Mint, Eva Adams; and R.S. Yeoman of Whitman Publishing Co. This formal ceremony at the Denver Mint on Jan. 4, 1968, was the return of the mint mark.
Due to the lack of mint marks on coins from 1965-67, it is not known how many coins were produced by the three branch mints. What percentage of coins do you think were produced at the Denver Mint, the San Francisco Mint and the Philadelphia Mint?