The Barber dime is named for its designer, Charles E. Barber, who was Chief Engraver of the U.S. Mint from 1879 to 1916. The Mercury dime followed the Barber dime and was minted from 1916 thru 1945. The Mercury dime was replaced in 1946 by the Roosevelt dime, designed in honor of President Franklin D. Roosevelt, who died in April 1945.
The composition and diameter of the dime have changed throughout its mintage. Initially the dime was 0.75 inch (19 millimeters) wide, but it was changed to its present size of 0.705 inch (17.91 millimeters) in 1828. The composition initially 89.24 percent silver and 10.76 percent copper remained constant until 1837, when it was altered to 90 percent silver and 10 percent copper. Dimes with this composition were minted until 1966, although those minted in 1965 and 1966 bear the date 1964.
Beginning in 1965, dimes also began to be minted with a clad composition of copper-nickel; this composition is still in use today. The dime is a coin worth ten cents, or one tenth of a United States dollar. The dime is the smallest in diameter and the thinnest of all U.S. coins currently minted for circulation.
The 32nd President, Franklin D. Roosevelt, is featured on the obverse of the current design, while a torch, oak branch, and olive branch covering the motto E pluribus unum are featured on the reverse. Although other coins were eligible for an updated design (the design of any coin may be changed without Congressional approval after 25 years, the dime was chosen due to Roosevelt's work in founding the National Foundation for Infantile Paralysis, known as The March of Dimes.