Career
Born in Chicago, Grant began his career in the mid-1930s developing stories or writing scripts for mostly B movies. He collaborated with John Wayne on twelve projects, starting with Angel and the Badman (which he also directed) in 1947 through Circus World in 1964. Support Your Local Gunfighter was released in 1971, five years after his death.
Grant wrote numerous short stories that were published in Argosy, The Saturday Evening Post, Cosmopolitan, and Liberty, among others
Grant died from cancer in Burbank, California. He owned a cattle ranch in Winton in Merced County from the 1940s until his death.