Douglas Winter Numismatics - Liberty Head gold coins from the Philadelphia mint were struck from 1838 through 1908 in six different denominations. There are hundreds of individual issues and they range from extremely common to extremely rare. These coins tend to be less desired than their branch mint counterparts for at least four reasons:

The duration of many denominations is so long that they tend to not be collector-friendly for set builders.

They don't have the sex appeal of the Southern branch mint issues and are less popular as a result.

They contain many grade rarities which make set building very difficult.

Yours truly has never written a reference book about Philadelphia gold coins which leaves collectors "on their own" when it comes to purchasing coins.
Because of these factors (and more) there are probably more overlooked and subsequently undervalued gold coins from Philadelphia than from any other mint; maybe even more than from all of the other mints combined.
In this article, I'm going to discuss the first 14 "undervalued" P mint Liberty Head gold coins which pop into my mind. Rest assured, I could easily have tripled the size of this group - and I've tried to include as broad a mix of denominations as possible. Note that I'm focusing on dates which I feel are undervalued in all grades, not just in high grades. This keeps me from painting with a broad brush and stating, for instance, that "all No Motto half eagles in properly graded MS63 and finer are rare and undervalued."
1. 1865 Gold Dollar
In the Civil War gold dollar subset, the 1863 gets all the love (and has the highest price) but I have actually handled fewer 1865 gold dollars over the years. This date has a very odd pattern of survival with virtually no survivors in grades below AU55 or above MS65. Clearly this date didn't circulate and many were melted. Unlike many of the other gold dollars from this era, there are not many super-Gems known which were put away by collectors, dealers and hoarders at the time of issue.
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