Ron Guth:
In 1859, the New Orleans Mint bore the brunt of Half Dollar production, producing more of that denomination than either the Philadelpjia or San Francisco Mints - by far. Unfortunately, despite the larger mintage and the greater population of certified coins, the quality of the surviving examples is not as good as the coins produced at the other two Mints. The majority of certified Mint State 1859-O Half Dollars only rate MS62 to MS63. There are some higher quality examples, but they are quite scarce. The best example is the bright, blast white PCGS MS67 that has not re-appeared on the market since it last sold in 2006. Most of the 1859-O Half Dollars that we've seen appear to be well-struck, though the occasional coin will show weakness on the stars.