1829 Proof

The 1829 proof half dime occupies a unique place in American numismatics: at least one example was sealed inside the cornerstone of the second Philadelphia Mint building during the July 4, 1829 dedication ceremony. That coin is still there. Mint Director Robert Patterson oversaw the ceremony, and the choice to include a proof half dime in the cornerstone reflected the coin's dual significance as the first of a resumed denomination and the first American coin struck with close collar technology.

Total production was approximately 30 proof half dimes for the year, distributed among Mint officials, dignitaries, and early collectors. Walter Breen identified seven proof die varieties for 1829, suggesting that proof production was spread across multiple dies rather than concentrated on a single pair. The LM-2 variety is specifically associated with the cornerstone ceremony. Mint Director Patterson received his own 1829 proof half dime as a personal presentation, and the coin remained in the Patterson family until it was sold at auction in 2012.

Fewer than 15 total proof examples are estimated to survive across all varieties. The finest known grades PR67+ and sold for $102,813 at the D. Brent Pogue sale in May 2015. A PR67 earlier brought $103,500 at Heritage in January 2012. Any 1829 proof half dime that surfaces publicly is a significant event in the early American proof coinage market, and pricing reflects both the extreme rarity and the historical weight of the cornerstone connection.