1870-S

The 1870-S eagle stands as a landmark issue for two reasons that converge in a single year. It is the seventeenth annual eagle struck at San Francisco, and it belongs to the first year in which With-Motto eagles emerged from three working mints at once, with Philadelphia and the newly opened Carson City joining the western powerhouse. A reported delivery of just 8,000 pieces gave the issue an attrition profile from the start, and decades of melting and circulation wear have reduced the survivor pool to a sliver of that figure.

Survival estimates from CoinWeek place gradable examples at roughly 70 to 90 coins, with another 20 to 49 ungradable pieces surfacing in dealer inventories. Most known coins fall in the Fine to Extremely Fine band, with About Uncirculated examples genuinely scarce and Mint State pieces approaching unobtainable. Authentication should begin with the S mintmark itself, which demands close comparison against verified reference photographs because the much commoner 1870 Philadelphia issue has historically tempted alteration attempts; suspect any mintmark that shows tooling marks, raised metal at its perimeter, or a font that does not match the punch used across genuine S-mint eagles of the period. Confirm gross weight at 16.718 grams within standard tolerance and specific gravity near 17.2 consistent with the 90 percent gold alloy, and look for the somewhat granular surface texture characteristic of San Francisco production in this era rather than the brighter fields of contemporary Philadelphia strikes.

The 1870-S anchors the difficult early-1870s S-mint run alongside its peers from 1866-S Motto, 1868-S, 1869-S, and the 1871 through 1874 issues, all of which David Akers grouped together as comparable rarities. Recent auction history reflects this standing: Heritage realized $3,525 for an EF-40 example in January 2015, $5,170 for an AU-53 in April 2016, and $12,925 for an AU-58 in March 2014, while properly graded Uncirculated coins begin near $25,000 when they appear at all. Date-set builders typically settle for honest VF or EF specimens with original surfaces rather than chase higher grades that rarely come to market. For broader context on the type's evolution and Western production, see the Liberty Head Eagle series history.