1855-S

San Francisco struck 61,000 half eagles in 1855, its second year of production for the denomination and a dramatic step up from the legendary 268-coin emission of 1854. The new branch facility, opened in April 1854 to convert California placer gold into federal coinage, was still working through equipment limitations and an inexperienced workforce. Where 1854-S survives in only three or four known examples and stands among the most sought-after American gold rarities, 1855-S is the year San Francisco found a workable production rhythm. Output was still a fraction of what Philadelphia struck that year, and the coin shipped almost entirely into West Coast commerce, where boomtown circulation chewed through the survivors before East Coast collectors took notice.

Genuine pieces weigh 8.359 grams on a 21.6 mm planchet of 90 percent gold and 10 percent copper, with a reeded edge and the small S mintmark below the eagle on the reverse. Two authentication checks help. First, weight: an underweight piece in the high 8.2-gram range or below is suspect, as cast or thinned counterfeits rarely hold true gold-alloy density. Second, mintmark integrity. Added-S work is less common than added-C or added-D fakes since San Francisco gold tends to carry lower premiums than Charlotte or Dahlonega issues, but the S should rest cleanly on the field rather than show a tooled or raised seam at its base. Strikes are typically soft on Liberty's hair curls and on the eagle's neck and shield, a signature of the early San Francisco presses.

The surviving population is estimated at roughly 250 to 350 coins across all grades, with most examples falling between Very Fine and Extremely Fine. About uncirculated and Mint State pieces are genuinely scarce and command sharp premiums when they appear at major auction. The 1855-S sits in the second tier of Coronet half eagles from San Francisco, well below 1854-S, 1864-S, and 1875-S in absolute rarity but clearly above the more available 1856-S through 1860-S issues that follow. Mid-grade examples have traded in the low to mid four figures at recent Heritage and Stack's Bowers sales, with sharp original AU coins reaching the upper four figures. For broader context, see the Liberty Head Half Eagle series history.