Ron Guth: The 1831 Half Cent is the source of great debate in the numismatic community. One camp calls this a Proof-only date; the other says that some 1831 Half Cents were released intoi circulation.
Mint Reports show a mintage of 2,200 1831 Half Cents. However, records from this period are known to be incorrect, with mintages often reported in the wrong year. Those who claim that some were made for ciruclation point to this mintage figure and the fact that a high percentage of the known population exists in circulated condition. To date, no one has come up with a convincing, high-grade business strike, but there are several pieces that are clearly circulated Proofs.
Those who support the Proof-only theory dismiss the official mintage figure and they claim that all of the circulated examples started out as Proofs. However, they are unable to explain why so many of the coins exist today and why so many of them are in circulated condition. No other Proof Half Cents of this era follow this pattern, but the 1831 shares a close kin-ship with the 1841 Quarter Eagle (another source of considerable debate over its true status as a Proof or a business strike).