Winged Liberty Head Dime (Mercury) (1916–1945)

Although most commonly referred to as the Mercury dime, the coin does not depict the Roman messenger god. The obverse figure is a depiction of Liberty wearing a Phrygian cap, a classic symbol of liberty and freedom, with its wings intended to symbolize freedom of thought. Designed by noted sculptor Adolph A. Weinman, the Winged Liberty Head dime is considered by many to be one of the most beautiful U.S. coin designs ever produced. The composition (90 percent silver, 10 percent copper) and diameter (17.9 millimeters) of the Mercury dime was unchanged from the Barber dime.

Weinman (who had studied under Augustus Saint-Gaudens) won a 1915 competition against two other artists for the design job, and is thought to have modeled his version of Liberty on Elsie Kachel Stevens, wife of noted poet Wallace Stevens. The reverse design, a fasces juxtaposed with an olive branch, was intended to symbolize America's readiness for war, combined with its desire for peace. The fasces would later become a symbol of Italian dictator Benito Mussolini's Fascist National Party, leading some to criticize the dime's design.

The 1916-D issue of only 264,000 coins is highly sought after, due largely to the fact that the overwhelming majority of the dimes struck at Denver in 1916 carried the pre-existing Barber design. Thus, the 1916-D is worth up to thousands of dollars if it is in relatively fine condition. Many coins in this series exhibit striking defects, most notably the fact that the line separating the two horizontal bands in the center of the fasces is often missing, in whole or in part; the 1945 issue of the Philadelphia Mint hardly ever appears with this line complete from left to right, and as a result, such coins are worth more than usual for uncirculated specimens. No dimes bear the dates of 1922, 1932, or 1933. A valuable variety is an overdate, where 1942 was stamped over a 1941 die at the Philadelphia mint. A less obvious example from the same years is from the Denver mint.

Of particular interest to numismatists is the condition of the horizontal bands tying together the bundle on the fasces, on the coin's reverse. On well-struck examples, separation exists within the two sets of bands (known as Full Split Bands). Coins exhibiting this feature are typically valued higher than those without it.