1870-S

The 1870-S Seated Liberty Dollar is one of the most famous American numismatic rarities, with a documented surviving population of approximately 9 to 12 examples and no official Mint records of production. Researchers believe the 1870-S Seated Dollars were struck at the new San Francisco Mint building (opened in 1870) as cornerstone or presentation pieces, with some examples possibly placed inside the building cornerstone and others retained or distributed informally. The 1870-S carries the standard Christian Gobrecht obverse and the With Motto reverse that defines the Type 2 era, with the S mintmark positioned below the eagle on the reverse.

Authentication of an 1870-S Seated Dollar claim requires careful examination of strike quality, surface character, and pedigree documentation alongside institutional review. All known 1870-S Seated Dollars carry continuously traced pedigrees through every owner since first discovery in the late nineteenth century. PCGS, the Professional Coin Grading Service, and NGC apply rigorous authentication standards, with pedigree documentation accompanying confirmed examples in every certified transaction. The 1870-S is among the most carefully tracked coins in American numismatics, alongside the 1804 Silver Dollar and the 1894-S Barber Dime.

The 1870-S is a recognized Key Date and one of the apex U.S. silver-coin rarities of any series, standing among the most-discussed coins in nineteenth-century U.S. numismatics. The 1870-S pairs with the 1870 Philadelphia and 1870-CC Carson City as the three-mint 1870 trio, with the 1870-S as the documented unique-class rarity at the apex. Auction records for confirmed 1870-S examples reach seven figures: the James A. Stack specimen graded PCGS MS62 (the only documented Mint State 1870-S and the finest known) sold for $1,092,500 at Stack's in May 2003, with the Eliasberg AU53 specimen and other circulated examples crossing $400,000 to $800,000 at major auction. Long-term Seated Dollar pricing structure has held a stable tier above silver bullion content for common dates, with registry-set collectors targeting top-pop Mint State examples where strike quality and surface preservation become the limiting factors on assigned grades. For the San Francisco Mint cornerstone theory and the broader 1870-S mystery, see the Seated Liberty Dollar series history.