Roosevelt was born as Kenneth Stanhope Sanderson in Meeker in Rio Blanco County in northwestern Colorado. He was an athlete and a cowboy in his youth. He started performing as a stuntman in 1916, his first work being on the filmHell's Hinges. He continued working as a stuntman as well as an actor throughout his long Hollywood career. Roosevelt served in the United States Navy during World War I. Although it has been said that he served aboard the USS Norfolk, and that it was sunk during that war, no record of a USS Norfolk being in service during World War I has been found. After World War I, Roosevelt returned to Hollywood to perform stunts in films as notable as The Sheik, the 1921 movie classic starring Rudolph Valentino and for which Valentino would become most remembered. Roosevelt's first acting role was in the 1924 film Down in Texas. He would star in thirty-seven films from 1924 to 1929, most of which were western films. He made a successful transition to "talking films", mainly because of his abilities as a stuntman. In 1930, he appeared alongside William Haines and Leila Hyams in Way Out West, which continued him on the path of western film roles, mostly in Poverty Row films but he also made small or uncredited appearances in major films. During the 1930s he appeared in 66 films—some in which he both acted and did stunt work—almost all being westerns, and appeared with such notable actors and actresses as Harry Carey, Hoot Gibson, Gloria Stuart, Joel McCrea, Edward G. Robinson, Bette Davis, and Humphrey Bogart. He also was a frequent stand in for Ronald Colman beginning with Clive of India. In 1939 he both performed stunts and had a minor role in the Claire Trevor-John Wayne classic Stagecoach, and in 1940 he appeared, uncredited, again with John Wayne in The Man from Dakota, in which he also performed stunts. Throughout the 1940s he both appeared in or performed stunts in 32 films, most notably alongside Randolph Scott and Lloyd Bridges in Abilene Town. During World War II he interrupted his film career by enlisting in the U.S. Coast Guard. In the 1950s, he appeared in sixty-five episodes as an unnamed townsman on the ABC/Desilu television series, The Life and Legend of Wyatt Earp, with Hugh O'Brian in the title role. Jimmy Noel appeared similarly in 144 episodes of the same series. From 1950 through 1962 he appeared in or perform stunts in thirty-six films and two television series. In 1957 he appeared uncredited as a Townsman in The Lonely Man. He retired after 1962 with his last appearance being uncredited in the John Wayne and James Stewart film The Man Who Shot Liberty Valance. He returned home to Meeker, Colorado, where he was living at the time of his death on October 6, 1973, at the age of seventy-five.
