Thanks to a large mintage of over 7 million coins, the 1858-O Half Dollar is a common coin in most grades. Mint State examples are plentiful in MS62 and MS63, but the population begins to drop off quickly in MS64 and above. The finest 1858-O Half Dollar is a single PCGS MS66 formerly of the Eugene Gardner Collection (not a surprise since Mr. Gardner had such an extraordinary taste for superb quality Seated Liberty coinage).
Numerous 1858-O Half Dollars were recovered from the wreck of the S.S. Republic in 2003 off the coast of Georgia. Most saw limited circulation before the ship went down in 1865, but all were affected by salt water corrosion, thus they show nice details, but lightly pitted surfaces.