In 1916, a new Dime design was introduced to replace the old Barber design that had been in use since 1892.  Designed by A.A. Weinman, the new design featured a portrait of Liberty facing left, wearing a winged cap.  Because of the resemblance to the Roman god, Mercury, the coin became known popularly as the "Mercury Head" Dime.  The reverse blends a Roman fasces (ax surrounded by a tied bundle of sticks) and an olive branch, indicating America's military readiness but also their desire for peace.  The Mercury Head Dime series is one of the most popular in all of American numismatics.  Apart from the 1916-D and 1942 overdates, most dates can be obtained with little difficulty.  However, several of the dates are extremely rare in high grade.  The most desirable issues are those with Full Split Bands on the reverse, which means all of the bands that hold the fasces together on the reverse must be clearly and completely separated.  While much attention is focused on the central bands, the bands on the ends of the fasces must be separated, as well.  Again, many dates are extremely rare in Gem condition with Full Split Bands.

*Credit: Ron Guth, PCGS CoinFacts