The following is excerpted from Clifford Mishler’s Coins: Questions & Answers
Q: Is there any explanation for why the New Orleans half dollar of 1861 is not worth more than its present valuation, when the U.S. Mint report officially reports that only 330,000 were struck? Other coins of the period with similar mintages are valued much higher.
A: In addition to the “official” U.S. mintage, another 1,240,000 1861-O half-dollars were struck in the name of the government of Louisiana after it seceded from the Union, with the Mint having been seized by the state militia on January 31, 1861, at the beginning of the Civil War. Two months later, the Mint was turned over to the Confederate States of America, under whose control 962,633 additional halves were subsequently struck between then and May 31, 1861, when continued operation of the facility as a mint was discontinued due to a lack of bullion. Thus, the combined mintage total was 2,522,633. All three mintages were struck utilizing regular U.S. dies prepared for and received by the Mint prior to the secession, and cannot be distinguished from the much smaller quantity struck as U.S. issues.