Keane responded by giving Zippy an appearance in "Family Circus."
Born in 1922, Keane taught himself to draw in high school in his native Philadelphia. Around this time, young Bill dropped the second "L'' off his name "just to be different."
He worked as a messenger for the Philadelphia Bulletin before serving three years in the Army, where he drew for "Yank" and "Pacific Stars and Stripes." He met his wife, Thelma ("Thel"), while serving at a desk job in Australia.
He started a one-panel comic in 1953 called "Channel Chuckles" that lampooned the up-and-coming medium of television. (In one, a mom in front of a television, crying baby on her lap, tells her husband: "She slept through two gun fights and a barroom brawl — then the commercial woke her up.")
He moved to Arizona in 1958 and two years later started a comic about a family much like his own. Keane and his wife had a daughter, Gayle, and sons Glen, Jeff, Chris and Neal — one more son than in his cartoon family.
"I never thought about a philosophy for the strip — it developed gradually," Keane told the East Valley Tribune in 1998. "I was portraying the family through my eyes. Everything that's happened in the strip has happened to me.
"That's why I have all this white hair at 39 years old."
Thelma Keane died of Alzheimer's disease in 2008 and was the inspiration for the Mommy character in the comic strip.
When his wife died, Keane called her "the inspiration for all of my success. ...When the cartoon first appeared, she looked so much like Mommy that if she was in the supermarket pushing her cart around, people would come up to her and say, 'Aren't you the mommy in 'Family Circus?'"
She also served as his business and financial manager.
Arizona and Keane had a mutual influence on each other. Keane's work can be found all around — from children's centers to ice cream shops.
Likewise, Arizona could also be found in Keane's work.
A 2004 comic saw the family on a scenic lookout over the Grand Canyon with the children asking "Why are the rocks painted different colors" and "What time does it close?"
Jeff Keane said those memories endure.
"He was just our dad. The great thing about him is he worked at home, we got to see him all the time, and we would all sit down and have dinner together. What you see in the 'Family Circus' is what we were and what we still are, just different generations."
Associated Press writer Matt Moore in Philadelphia contributed to this report.