The Roosevelt Dime appeared in 1946 to commemorate the life of President Franklin D. Roosevelt who had died in office the year before. It replaced the so called "Mercury Head" Dime.
The portrait on the obverse side of the coin was created by John R. Sinnock, then Chief Engraver at the mint. Sinnock's initials (JS) appear at the base of Roosevelt's neck near the bottom rim of the coin to the left of the date. The Reverse image is a torch flanked by an oak branch and an olive branch.
Mint marks are D for Denver, S for San Francisco, and P for Philadelphia. Through 1964 the mint mark appears on the reverse side of the coin at the base of the torch on the left side. Starting in 1968, the mint mark was moved to the obverse side, just above the date. Mint marks are absent from coins minted in Philadelphia prior to 1980 and from all dimes minted from 1965 through 1967 (regardless of mint location). In Uncirculated Coin sets produced in 1996 (but not circulated coins), Roosevelt dimes with the Mint Mark W (West Point Mint) appeared.
Initially Roosevelt Dimes were composed of 90% silver and 10% copper. In 1965, however, silver coins were replaced with clad coinage in which a pure copper core was covered with an outer layer of copper-nickel. The edge of the dime is reeded (grooved) to discourage counterfeiting and to make the filing away of silver evident. Although the dime is no longer composed of precious metal, the reeding is retained in today's coins as a decorative feature and to help the visually impaired to distinguish dimes from similarly-sized pennies.