The Missing “P”

1965 Quarter


Washington QuarterThe history of United States coinage began with congress passing the Coinage act of 1792. This legislation gave the relatively newly formed federal government the power to establish a mint in Philadelphia and begin the production of coins. The next year 1793, the first official strikes began with the half cent and cent, other denominations followed in 1794 with the half dime, dime, half dollar and dollar, with the quarter being introduced in 1796. The Philadelphia mint was the sole producer of United States coinage until 1838.

This short history starts to unravel the mystery of the missing “P.” As the only mint at the time, there was no need for a mint mark. As other mints were established, they began to use mintmarks:

Since all the other mints were using mint marks it was not considered that Philadelphia should or needed to use one.  This began to change in 1979, with the Susan B. Anthony dollar being the first coin to bear the “P” mint mark. The next year (1980), the “P” was added to all denominations except for the cent.  In 2017, the entire production on Philadelphia Lincoln cents were struck with a “P” mint mark to commemorate the 225th anniversary of coins being stuck in Philadelphia.

All this missing “P” business may leave some confused, while others attempt to take advantage of this oddity.  Over the years, there have been a handful of errors in which “S” mint proof coins have been struck without their proper mint marks, making them appear to be Philadelphia coins.  It is important to understand that proof strikes and regular strikes are significantly different.  These errors occurred in the following years and denominations:

Penny Example

The coins listed above are all proof strikes missing their mint marks.  Proof coins were sold by the United States mint in annual sets for a premium over their face value and are not coins that were released for circulation.  As such, if you have one of these dates in your pocket change with no mint mark, it is almost certainly a standard circulation strike Philadelphia coin.