"The only reason is that when I was a kid, the TV show 'Father Knows Best' took place in the town of Springfield, and I was thrilled because I imagined that it was the town next to Portland, my hometown," Matt Groening told Smithsonian magazine.
"When I grew up, I realized it was just a fictitious name," Groening said. "I also figured out that Springfield was one of the most common names for a city in the U.S. In anticipation of the success of the show, I thought, 'This will be cool -- everyone will think it's their Springfield.' And they do."
Thirty-five U.S. cities and towns are named Springfield, with the Massachusetts Springfield the oldest, settled in 1636, and Missouri's the most populous, at 160,000.
Springfield, Ore., next to Eugene, was incorporated in 1885 and has a population of 60,000.
It doesn't look like the Springfield in the Fox Broadcasting Co. animated sitcom, whose geography and surroundings change for whatever an episode's plot calls for.
The show, which parodies American culture, has also been deliberately evasive about the subject, providing contradictory clues and impossible information about an actual geographic location.
Groening said he hadn't revealed which Springfield inspired the town because he didn't "want to ruin it for people, you know?"
"Whenever people say it's Springfield, Ohio, or Springfield, Massachusetts, or Springfield, wherever, I always go, 'Yup, that's right,'" he told the magazine.
The Homer Simpson character posted several messages on Twitter after the location was revealed, including:
"That's right, the Simpsons live in Oregon -- California's toupee"; "Crap, we live in Oregon? I mean, Go Ducks!" and "Congratulations, Oregon. Your taxes will pay for my jail time."
"The Simpsons," which debuted Dec. 17, 1989, and is in its 23rd season, will refer to Springfield's origins in the Bart Simpson chalkboard gag during the opening credits of Sunday's episode, Entertainment Weekly reported.