In the years since the U.S. opened multiple mints, there have been a number of instances in which coins have been struck without a mintmark letter. NGC’s David Lange examines the history of these anonymous coins.
Until 1838, all United States coins were struck at a single mint located in Philadelphia. In that year, branch mints were opened in three southern cities, and each of the new mints utilized a specific letter to distinguish its products from those of the mother mint in Philadelphia. That practice has continued to the present day, each new minting facility having its own unique letter or — in the case of Carson City, Nevada — a pair of letters. The sole exception to this rule is that letter “D” was used for both Dahlonega, Georgia and Denver, Colorado, though at different periods separated by many years.
There have been, however, instances in which no mintmark letter appears on United States coins that are known to have been struck outside of Philadelphia. In some cases, this was an accidental oversight, but more often, it was done as a matter of expediency or government policy. There was even a three-year period during which the omission of mintmarks was mandated by law. This month’s column will take a look at such anonymous coinages.
For many years, it was assumed that the 1840 half dollars having the retrograde Medium Letters reverse used in 1838-39 were products of the Philadelphia Mint, as they bear no mintmark. A more careful examination by numismatists, however, gradually began to chip away at this assumption. In 1982-83, I wrote a pair of articles for The Gobrecht Journal in which I related that this variety was smaller in diameter than normal 1840 half dollars. In fact, the diameter was that typical of 1840 half dollars from the New Orleans Mint. Just a few years later, fellow researchers Randy Wiley and Bill Bugert were able to identify the two obverse dies used with this unique reverse as having been used for other 1840-O varieties in which normal Small Letters reverses were employed. This proved what I had previously suspected — that the 1840 Medium Letters half dollars were actually products of the New Orleans Mint.
It may be that many USA coins passing as “P” Mint issues were actually struck from dies that simply left the Engraving Department improperly prepared. Rarely, however, are these errors distinguishable from ordinary coins of the Philadelphia Mint. Only when a coin is known to have been manufactured solely at a branch mint is the oversight spotted. Such was the case with the Fort Vancouver Centennial half dollars dated 1925. The entire mintage was produced at the San Francisco Mint, yet not a single example is known to have the “S” mintmark. It was simply left off the dies without explanation.
1922 was a year of nationwide economic recession, and few additional coins were needed. The Denver Mint, however, received a sudden order for several million cents early in the year. Since it was not anticipated that more would be coined anytime soon, the number of dies employed was very small, causing these dies to become very eroded from overuse. The result was that both the date and mintmark began to fade away as the dies wore and were repeatedly refinished. The mintmark disappeared altogether on at least one obverse die, and for decades afterward, collectors were puzzled by and drawn to the mysterious 1922 cents apparently made at Philadelphia. Had that mint actually struck one-cent pieces in 1922, the “plain” cents would have gone without special notice. Instead, they became popular and costly collectibles.
In an attempt to cope with a nationwide coin shortage during the 1960s, Congress ordered that mintmarks be omitted from all coins dated 1965 and later. This order was rescinded late in 1967, to be effective with the 1968 coinage, but the Philadelphia, Denver and San Francisco Mints all contributed to the anonymous coinage of 1965-67. An exact breakdown of which mints produced which coins in which years may be found in my column for the NGC October, 2003 newsletter.
Perhaps the most obvious mintmark omissions of recent decades have been the result of human error. When the San Francisco Mint took over production of proof coins in 1968 (it actually began with the Special Mint Set coins of 1965-67), the stage was set for a series of embarrassing gaffes. In that very first year, the “S” mintmark was omitted from a single die used to strike proof dimes. This same error recurred in 1970, allegedly in 1975 (I’ve never seen an example of this date), and in 1983. It also happened with nickels in 1971 and with cents in 1990.
A little-known fact is that mintmarks have been omitted from San Francisco proof coins at other times, too, but the erroneous pieces were caught before release. Some years ago, I interviewed Tom Miller, Officer in Charge at the San Francisco Assay Office (as the mint was known from 1958-88), and he revealed that the complete list of S-less proof coins included quarters and halves. He did not reveal the exact dates, but he said that the last instance known to him occurred with the half dollar around 1982.
The mints at San Francisco and West Point both struck circulating coins from the mid-1970s and, for the next ten years or so, all without mintmarks. Since that time, the non-proof editions of the American Eagle bullion coins have been minted at various facilities without identification. It will challenging for future researchers to reconstruct this history, as the Mint Director’s report in recent decades has read more like a brochure for stockholders than the technical/historical document it once was.
David W. Lange's column, “USA Coin Album,” appears monthly in Numismatist, the official publication of the American Numismatic Association.