Allen began his singing career on radio station KOY in Phoenix, Arizona, after which he became better known as a performer on the National Barn Dance on WLS in Chicago.

When singing cowboys such as Roy Rogers and Gene Autry were very much in vogue in American film, in 1949 Republic Pictures in Hollywood gave him a screen test and put him under contract.
Beginning in 1950, Allen starred as himself in 19 of Hollywood's Western movies.
One of the top-ten box office draws of the day, whose character was soon depicted in comic books, on screen Allen personified the clean cut, God-fearing American hero of the wild West who wore a white Stetson hat, loved his faithful horse Koko, and had a loyal buddy who shared his adventures.
Allen's comic-relief sidekick in his first few pictures was Buddy Ebsen and then character actor Slim Pickens.
Allen began his singing career on radio station KOY in Phoenix, Arizona, after which he became better known as a performer on the National Barn Dance on WLS in Chicago.
When singing cowboys such as Roy Rogers and Gene Autry were very much in vogue in American film, in 1949 Republic Pictures in Hollywood gave him a screen test and put him under contract. Beginning in 1950, Allen starred as himself in 19 of Hollywood's Western movies. One of the top-ten box office draws of the day, whose character was soon depicted in comic books, on screen Allen personified the clean cut, God-fearing American hero of the wild West who wore a white Stetson hat, loved his faithful horse Koko, and had a loyal buddy who shared his adventures. Allen's comic-relief sidekick in his first few pictures was Buddy Ebsen and then character actor Slim Pickens.
Rex Allen