Over the next several months, North made television appearances on such shows as 77 Sunset Strip, Rescue 8, Cheyenne, Bronco, Colt .45, and Sugarfoot, and broke into feature films with roles in The Miracle of the Hills and The Big Operator until, in early 1959, almost one year after he had first auditioned, MacMillan contacted North's mother to tell her that her son had been chosen to play the role of Dennis "The Menace" Mitchell.