In which year was the "Roosevelt" dime first put into circulation?

The dime has featured the likeness of President Franklin D. Roosevelt since 1946. Roosevelt had died in April of 1945. Up until that time, the American dime's obverse had the "Winged Liberty Head". This is also refered to as the "Mercury" dime from 1916-1945. The obverse of a coin is the side of a coin or medal bearing the head or principal design.

After Roosevelt's death, an effort spearheaded by Congressman Ralph Daughton was launched to have the image of the President on the American dime. This was primarily due to Roosevelt's efforts to raise money for polio research, which would later be known as the March of Dimes. John R. Sinnock, a chief designer with the U.S. mint, was the person who developed the design for the Roosevelt dime.

This first rendition of the design was rejected in the fall of 1945. A second design, was accepted on January 6, 1946. The dime with the new obverse began circulation on January 30, 1946, which would have been Roosevelt's 64th birthday.

From the time the dime was first introduced, it has had 6 different obverses since 1796. These designs are listed below.

Draped Bust 1796–1807

Capped Bust 1809–1837

Seated Liberty 1837–1891

Barber 1892–1916

Winged Liberty Head (Mercury) 1916–1945

Roosevelt 1946–present