Inspiration for Dennis the Menace
Ketcham is the inspiration for the comic strip Dennis the Menace, created by his father Hank Ketcham. When Ketcham was four years old, he once refused to take a nap and somehow messed up his whole room. Hank tried many possible kid names for the character he was drawing on his desktop in his home at Carmel, and translated them into some rough pencil sketches, but they seemed unsuitable for the character. Later his studio door flew open and his wife Alice, in utter exasperation, exclaimed, "Your son is a menace!" Thus the "Dennis the Menace" name was used. The "menace" epithet and the image of the tornado stuck. The character of Henry Mitchell bore a striking resemblance to Ketcham himself, who also became a fixture in the strip. The comic strip that was inspired by Ketcham, was carried by 16 newspapers within five months. By May 1953, 193 newspapers in the United States and 52 abroad were carrying the strip to 30 million readers. It is now written and drawn by Ketcham's former assistants, Marcus Hamilton and Ron Ferdinand, and distributed to more than 10,000 newspapers in 48 countries and 19 languages by King Features Syndicate 
Unlike his cartoon alter ego, Ketcham did not lead a storybook life. He had learning disabilities as a boy. An alcoholic mother and a father with a busy work schedule meant there was little time left for him.
After his mother filed for divorce in 1959, he was sent to a boarding school. Soon after, his mother died from an accidental drug overdose at age 41. His father remarried to Jo Anne Stevens and moved the family to Geneva, Switzerland. Ketcham had a difficult time in Swiss boarding school, so his father sent him to a boarding school in the United States while Hank and his new wife remained in Europe.
After graduating, Ketcham joined the Marine Corps and served in Vietnam. Upon his return, he was treated for post-traumatic stress disorder and drifted from one low-paying job to another. In the late 1970's Dennis worked at the old Ohio Penitentiary in Columbus, Ohio. By 1990, he was living in Ohio and estranged from his father. Hank commented on his own marital breakup and his son's loss of privacy, "These things happen, but this was even worse because his name was used. He was brought in unwillingly and unknowingly, and it confused him."
Meanwhile, Hank Ketcham, now a multi-millionaire, divorced and married the former Rolande Praepost with whom he had two children, Scott and Dania. Hank, who died in 2001, told People in 1993, "I hear from Dennis about once a year, mostly when he needs money." Ketcham also married, divorced, remarried and is estranged from his daughter.
- Weinraub, Judith (1990-05-05). "Dennis's' Dear Old Dad". The Washington Post.
- "Dennis Ketcham". CoolQuiz.com. Retrieved 2007-11-24.
- "Hank Ketcham, Father of Dennis the Menace, Dies at 81". The New York Times. 2001-06-02. Retrieved 2007-11-24.