The Years of No Mintmarks

tarting in 1838 with the inauguration of the New Orleans branch mint, almost every year saw newly mintmarked coins in circulation.
    Due to a shortage of cents in the 1960s, the director of the U.S. Mint took a drastic step and eliminated the mintmark from all of our coins for 1965, 1966, and 1967.
    The theory was that somehow, coin collectors (or hoarders) were creating shortages of cents and other coins by stashing away the mintmarked coins ("S" for San Francisco and "D" for Denver).
    Coins minted in Philadelphia at the time bore no mintmark (except on wartime nickels dated 1942-1945).
    "S" mint cents were last made in 1955. "S" mint dimes were also last minted in 1955. From 1956 to 1964, only "D"-mintmarked coins were made. Philadelphia Mint coins had no mintmark.
    The Mint suspended the manufacture of proof sets in 1965, 1966, and 1967 for similar dubious reasons. Instead, to meet the demand from collectors for special sets from the Mint, a new category was created: the "Special Mint Set."
    The 1965 version came in pliofilm-sealed packets with five coins very similar to the mint sets issued in that era — the cent through the half dollar — and for the most part, they were of no better quality than the business-strike issues shipped out in mint-sealed bags.
    These sets never gained any real popularity and sell for about the same now as they did 35 years ago.
    From collector comments (mostly complaints), the Mint created newer versions of the Special Mint Set (SMS) for 1966. This time, polished coins were used for the SMS, and they were sealed in a hard plastic case similar to the custom holders used by Capital Plastics for older proof sets.
    These sets were hardly any different in most cases from the proof sets of 1964 and earlier and gained immediate respect among collectors. In fact, many of these single coins are as popular as their earlier proof-set counterparts and sell for equivalent premiums.
    Because three of the coins are 90 percent silver, their prices vary widely as the price of silver fluctuates on the open market. The 1967 sets also contain polished versions of the mint-issued coins and often cannot be distinguished from earlier proof coins.
    It was evident from collectors' surveys and numismatic organizations that the removal of mintmarks did not influence hoarding or the circulation of our coinage. In 1968, the Mint resumed adding mintmarks to our coins.
    In addition, the Mint resumed the issuance of proof sets — this time in hard plastic cases as opposed to the 1964 version of pliofilm.
    Further, the newly issued proof sets included mintmarks, whereas proof sets of the past were made only in Philadelphia and the coins bore no mintmarks. The new proof sets were made in San Francisco and all five coins had the "S" mintmark.
    In addition, cents minted in San Francisco for general circulation had the "S" mintmark, which ran from 1968-1974. Thereafter only proof coins bore the "S" mintmark.