Ron Guth:
The 1864 Half Dollar is a great date with a low mintage. Mint State examples are not particularly scarce, which is probably due to the discovery of some of them in the so-called "Guatemala Hoard" in the 1950's (other dates were included in the hoard, as well). Most Mint State 1864 Half Dollars are of average quality, though there are some outstanding examples, including a tiny population at the MS67 level. Most 1864 Half Dollars exhibit strong strikes -- the best ones show full feather and fletch details on the reverse.