The 1858-O $20 double eagle is a great rarity, with fewer than 150 coins believed to exist in all grades. When one can be found, high grade coins usually show prooflike surface, especially on the reverse, a quality typical of double eagles minted in New Orleans. The strike is typically poor, with weakness across most of Liberty's hair elements. Scarce in all conditions, the majority of survivors are confined to Very Fine and Extremely Fine grades, with AU examples proving to be very rare. Just five or six Mint State pieces are known, the numerically finest of which is an NGC-graded MS-63, though Doug Winter believes the Bass specimen, currently certified as MS-62 (PCGS), is a finer coin. Certified grades are often inconsistent, making comparisons difficult.

Among early double eagles, the rarest of the rare are New Orleans coins in Mint State. The 1858-O is a low mintage issue with just 35,250 coins struck. The vast majority of examples were consumed by commercial use, and most numismatic scholars accept an estimate of only 150 to 200 pieces extant in all grades. The typical survivor grades EF or AU and is likely to trace its provenance to a group of circulated examples that entered numismatic channels during the 1990s. Mint State coins are exceedingly rare with Doug Winter (Gold Coins of the New Orleans Mint: 1839-1909, 2006 edition) accounting for just six or seven examples at any Mint State level. Four of the Uncirculated survivors are from the treasure recovered from the S.S. Republic shipwreck.

The S.S. Republic foundered in a hurricane off the coast of Georgia in 1865 shortly after the end of the Civil War. At the time of its loss, the ship was carrying $400,000 in silver and gold from New York City to New Orleans. Located in 2003 and subsequently salvaged by Odyssey Marine Exploration, the shipwreck yielded a treasure of 51,000 coins and 14,000 other artifacts. Among the coins were numerous double eagles from the 1850s and 1860s, including a number of condition rarities such as the 1858-O.

The example to the left was sold by Stack's Bowers Galleries in November 2017 as part of the Rarities Night Auction, where it realized $156,000.