Ron Guth:
The 1864 Dime is a wonderful date with an extremely low mintage of only 11,000 coins. As in 1863, the San Francisco Mint was the big producer of Dimes this year. Despite the small mintage, the 1864 is an excellent value, especially in high grade. For instance, the 1864 and 1864-S Dimes are worth almost the same amount in MS63 -- even though the 1864-S has a much larger mintage.
Seated Liberty Dime researcher, Gerry Fortin, identified two die pairs for this date, both of which were used to strike Proof versions. One of the die pairs was later used to make the small number of coins for circulation. As expected, many of these coins are Prooflike and can sometimes be mistaken as Proofs (which are actually worth less than Mint State examples).