1870 Proof

The 1870 proof half dollar is the fifth annual delivery of the Type 5 With Motto subtype and lands in the same calendar year that the Carson City Mint opened for business, though no Carson City proof half dollars were struck and the entire proof run stayed at Philadelphia. John Dannreuther places original delivery at approximately 1,000 pieces, the largest single-year proof half run of the post-Civil War era to that point, reflecting growing subscriber rolls to the annual silver proof set program. The 634,900 figure shown on this page is the Philadelphia business-strike delivery and has no bearing on this proof entry, which was a separately accounted medal-press run from polished dies. Modern census data place survival at Sheldon R-4 (roughly 76 to 200 known across all grades, the standard scale specialists use to describe survival), with a meaningful share of the original 1,000 believed to survive in collectible condition.

Authentication rests on structural diagnostics rather than mirror depth alone. A genuine 1870 proof reads as deeply mirrored watery fields with controlled die-polish lines visible under a 10x loupe (a jeweler's magnifier), set against frosted devices on the earliest die states, with the motto scroll above the eagle fully struck and IN GOD WE TRUST sharp on both sides of the central fold. Rims must be fully squared and raised perpendicular to the field, the signature of multiple medal-press blows rather than a single business-strike impression. Denticles (the tooth-like beads ringing the rim) should be sharp and fully formed, with pinpoint star centrils and razor-crisp hair and drapery detail on Liberty. Weight is load-bearing at 12.44 grams on a .900 fine silver planchet, diameter 30.6 millimeters, with a reeded edge; anything off-weight or off-diameter is disqualified outright. The recurring risk on this date is the prooflike business strike pulled from polished circulation dies during the 634,900-piece commercial run, which can mimic the reflective look without the squared rims and perpendicular denticles of a true proof. PCGS or NGC encapsulation is the working standard for any candidate offered outside a known specialist holding.

For collectors, the 1870 sits in the middle of the early With Motto Philadelphia proof run, priced behind the 1866 first-year-of-motto date but in line with the 1867 through 1872 cluster. The Regular classification on this page follows site convention for proof entries; rarity and historical weight live in the prose, not the badge. Cameo and deep cameo subsets price well over standard mirrors, and specialists building the 1858 through 1891 Philadelphia proof run treat the 1870 as a routine but not throwaway acquisition. Type collectors sometimes pursue this date specifically as the Carson-City-opening-year proof half, the only proof half from a year in which CC business strikes also exist. For broader context on the motto transition, the With Motto subtype, and the Carson City Mint's entry into the series, see the Seated Liberty Half Dollar series history.