Certified Brown Percentage: 14%
Certified Red and Brown Percentage: 65%
Certified Red Percentage: 12%
Certified Cameo Percentage: 9%

The first of the Reconstruction era Proofs in the Indian cent series, the 1866 has an estimated mintage of 725 coins. Only a single die pair is known, the obverse with microscopic roughness to Liberty's cheek due to rust in the die. The reverse die is the same that the Mint used to strike Proof 1865 cents of the scarce Snow-PR1 variety. As third party certification data makes clear, the Proof 1866 is not as scarce as the Proof 1865 in an absolute sense, although it is just as rare in the finest grades.

The example to the left was sold by Stack's Bowers Galleries in the November 2011 Baltimore Auction, where it realized $6,325.