The stuttering wasn’t just some bizarre character choice — it was his vaudeville shtick. As a child he’d had a horrible, natural stutter, which he later overcame. He first went into vaudeville as a concert violinist, but he eventually learned that there was more money in being a stuttering comedian. He went into movies just as talkies were coming in, and found plenty of work, mostly in westerns. For many years, he was the comical sidekick to a singing cowboy named Eddie Dean. He also worked constantly in television, until his death in 1962.
To find out more about these variety artists and the history of vaudeville, including Rosco Ates, consult No Applause, Just Throw Money: The Book That Made Vaudeville Famous