PORTLAND, Ore. (AP) — One of the best-kept secrets in television history has been revealed, with "The Simpsons" creator Matt Groening pointing to Springfield, Ore., as the inspiration for the animated hometown of Homer and his dysfunctional family.

Groening told Smithsonian magazine, published online Tuesday, that he was inspired by the television show "Father Knows Best," which took place in a place called Springfield. Springfield, Ore., is 100 miles south of Groening's hometown of Portland.

"When I grew up, I realized it was just a fictitious name," Groening told the magazine (http://bit.ly/HqiT4E). "I also figured out that Springfield was one of the most common names for a city in the U.S.