In 1916, the three silver denominations currently minted in the United States were given new designs. The old designs, which had been in use since 1892, featured the same obverse for all three denominations and had become unpopular with the majority of the public. An earlier change had been prevented by a law passed in 1890 that required a coin design to be in use for at least 25 years before it was eligible for replacement. Thus, the change took place at the earliest opportunity in mid-1916, when the new fiscal year began.
A public competition was organized to select designs for all three denominations. A number of different concepts were submitted, including a few by Charles E. Barber, who had designed the previous Barber Dime. On March 3, 1916, Mint Director Robert W. Woolley announced that the new dime would feature a design by Adolph Alexander Weinman. After the announcement, Weinman worked on finishing the design with the help of assistant engraver George T. Morgan. Production of the first Mercury Dimes began in June 1916.
The obverse features the head of Liberty, facing left and wearing a winged cap. The word LIBERTY is above, and IN GOD WE TRUST and the date are towards the bottom. The image was immediately mistaken for an image of Mercury, the Roman god of trade, profit and commerce, who was often depicted wearing winged shoes or a winged hat. Despite the incorrect association, the identification of the series as Mercury Dimes continued in use and remains the most common title for the series.
It is generally believed that Elsie Kachel Stevens, the wife of poet Wallace Stevens, was the model for Weinman's portrait of Liberty. She and her husband were tenants of an apartment owned by Weinman. In 1913, he had prepared a bust of Elsie, with her hair pinned under a cap including wings to symbolize liberty of thought. It is believed that he used this bronze bust as his basis for Liberty.
The reverse of the coin features the Roman fasces, comprised of an axe tied to a bundle of rods. Fasces were carried by Roman officials as a symbol of authority, although they came to carry different connotations in the later twentieth century. The inscription UNITED STATES OF AMERICA is around and the motto E PLURIBUS UNUM is to the right of the fasces. The detail in the horizontal bands is an area of focus for collectors of mint state Mercury Dimes. Examples displaying full bands can carry significant premiums.