THE Simpsons' hometown is based on Springfield, Oregon.
Matt Groening, creator of the animated series, has always kept the inspiration for the fictional Springfield in the show secret until now, saying it is based on a community 100 miles south of where he grew up in Portland.
He told Smithsonian magazine: ''Springfield was named after Springfield, Oregon.
''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.
''When I grew up, I realised it was just a fictitious name.
''I also figured out that Springfield was one of the most common names for a city in the US.
''In anticipation of the success of the show, I thought, 'This will be cool; everyone will think it's their Springfield.' And they do.''
Matt added the animated family's home Evergreen Terrace is named after the street he grew up on, while other characters in the series - which has run for 23 years - such as Reverend Lovejoy, school bully Kearney and the Simpsons neighbour Ned Flanders are all named after streets in Portland.
Four of the family members - Homer, Marge, Lisa and Maggie - are all named after Matt's own family, but he changed the name of the boy in the series from Matt to Bart.
Explaining why, he said it was because he ''had this idea of an angry father yelling 'Bart,' and Bart sounds kind of like bark - like a barking dog,'' which he thought would be funnier.
The town of Springfield, Oregon, was beaten by Springfield, Vermont, in a competition to host the premiere of 'The Simpsons Movie' in 2007.