1840

The 1840 Philadelphia half eagle is a coin of transition. Partway through the year, the Mint reduced the diameter from 22.5 mm to 21.6 mm and introduced a revised obverse hub with a smaller Liberty portrait. The post-transition coin set the physical standard that the series would follow for nearly seven decades. Coins struck on the older 22.5 mm planchet stock are catalogued separately as the 1840 broad-mill variety; this entry covers the standard 21.6 mm issue that emerged from the changeover. Reported Philadelphia mintage of 137,382 pieces is a combined figure spanning both formats.

The simplest authentication check is dimensional. A genuine post-transition 1840 measures 21.6 mm across and weighs 8.359 grams in 90% gold. A coin reading 22.5 mm belongs to the broad-mill catalog entry, not this one. The smaller-portrait obverse hub used here is the same one carried forward through 1908, so the head should match later Liberty half eagles in proportion rather than the taller, larger portrait used on 1839 strikings. Edge reeding is finer than on the broad-mill coins. Standard checks for added detail, tooled fields, and weight loss from cleaning apply, since most survivors saw circulation and any surface that looks too fresh for the wear pattern deserves a closer look.

For collectors, the standard 1840 Philadelphia is genuinely available in circulated grades and pricing tracks the type market more than the date itself. The interest concentrates at the upper end. Mint State examples with original luster are scarce because the coins worked as money, and gem survivors are rare enough that their appearances are tracked individually at auction. A type collector looking for a single Philadelphia coin from the first years of the series can usually find a pleasing VF or EF without much waiting. A date specialist working the early Liberty run will spend more time chasing a high-end example than the mintage number suggests. Variety collectors should be aware the broad-mill coin is a separate pursuit. For wider context, see the Liberty Head Half Eagle series history.