The show has teased about the real location of Springfield for years, but Simpsons creator Matt Groening lets Smithsonian magazine in on the secret: Homer's hometown is named after Springfield, Oregon. Why? Groening grew up in Portland watching Father Knows Best, which was set in "Springfield." As a kid, he just assumed it was the same Springfield near his hometown in Oregon. He didn't realize the city in Father Knows Best was fictional until years later.
"I also figured out that Springfield was one of the most common names for a city in the US," he adds. "In anticipation of the success of the show, I thought, 'This will be cool; everyone will think it’s their Springfield.' And they do." Bombshell TV trivia? Eh, maybe. ABC notes that Groening signed a plaque in 2007, "Yo to Springfield, Oregon—the REAL Springfield." (And he never explicitly says the family lives in the state, only that the town's name is inspired by Oregon's.) Click for the full interview, in which Groening also says that he wanted to name Bart's character "Matt" after himself, but figured it wouldn't fly in the pitch meeting.