The July, 1995 volume of the Gobrecht Eagle Quarterly had a thorough study of 1847-O Eagle die varieties, written by Joseph Philip. Combinations of four obverse dies and five reverse dies are known. The obverse die varieties are more important as they differ in the date: Normal date, Recut 18, Heavy repunched '1', and Heavy '7'. The reverse die varieties differ in position of the mintmark, which generally is located above the letters EN. One variety, however, has the mintmark located between N and D.