Ron Guth:
The 1858 Inverted Date Half Dime is one of the more interesting U.S. coin varieties. Apparently the engraver punched the date into the die upside-down, then punched it in correctly after realizing his mistake. The underlying, upside-down date is still visible in the die and clearly shows the mistake, even on lower-grade examples. This is a very scarce variety, and less than 10% of the certified 1858 Half Dimes show the Inverted Date. Mint State examples are rare. The typical Inverted Date appears in MS63 or MS65. A single PCGS MS66+ sist atop the Condition Census.