From the 1930s to the 1950s, the character became indelibly associated with actor William Boyd, who portrayed Cassidy first in a series of sixty-six films from 1935 to 1948, then in children-oriented radio and TV series, both of which lasted until 1952. Boyd's portrayal of Cassidy had little in common with the literary character, being instead a clean-cut, sarsaparilla-drinking hero who never shot first. The plots of the film, radio and TV series were generally not taken from Mulford's writings.
