His son, Dennis Ketcham, with whom he had with his first wife, Alice Louise Mahar, was the inspiration, that led to the creation of his so famous and still running and humorous comic strip "Dennis the Menace!". The comic strip is now being run daily, by two King Features' animators. Ron Ferdinand for the larger Sunday comic strip. Marcus Hamilton, for weekdays and Saturday, for the smaller comic strips. He was married to Jo Anne Stevens, they were married 1960 to 1977. Rolande Praepost was his third and final wife. His younger two, Dania and Scott Ketcham, were from his marriage, to Rolande Praepost.
