1866 Proof

Philadelphia struck 725 proof dimes in 1866 alongside an unusually thin 8,725-piece business-strike delivery, the smallest non-proof Seated dime mintage outside the 1873-CC No Arrows uniqueness. Reconstruction had barely begun, specie suspension remained in force, and the parent mint's hard-silver coining program ran on a skeletal schedule that produced more proofs than is typical relative to the matching circulation issue. The dime, unlike the half dollar and quarter, did not receive an IN GOD WE TRUST motto in 1866 because the planchet was too small to accommodate the ribbon banner that the Coinage Act of March 3, 1865 authorized. The proof continues under the Legend No Motto subtype that had governed the obverse since 1860, with "UNITED STATES OF AMERICA" arcing where Gobrecht's original stars had stood and the wreath reverse running unchanged.

Proof dimes of 1866 carried the Brilliant proof finish standard for the era, with deeply mirrored fields against frosty devices, and the Cameo contrast that later collectors prize on better strikes survives on a meaningful share of the population. Strike on the date runs sharp: squared rims, full denticles around both sides, complete drapery folds at Liberty's elbow, and crisp wreath leaves on the reverse. Authentication rests on the 2.49-gram weight standard set by the Coinage Act of February 21, 1853, the 17.9-millimeter reeded planchet, and the structural diagnostics of a multiple-blow medal press: rims perpendicular to the fields rather than rolled, fully formed devices, and watery die-polish lines visible under a 10x loupe (a jeweler's magnifier). Brilliant impaired proofs and prooflike business strikes from polished dies can imitate the surface look, so a PCGS, the Professional Coin Grading Service, or NGC, the Numismatic Guaranty Company, holder with a proof designation carries real authentication weight on this issue.

The 725 figure represents one of the larger Reconstruction-era proof mintages, but original sets routinely broke for type purposes and the surviving certified population is meaningfully thinner than the original delivery suggests. Most collectors approach the date through certified Cameo and Deep Cameo examples in PR-64 through PR-66, where supply meets demand at a level the market has settled into over several decades. The Regular rarity badge on this page follows site convention for proof entries; the catalog tier sits in the prose rather than the label. For the broader story of Gobrecht's design, the 1873 Coinage Act, and the series' proof program, see the Seated Liberty Dime series history.