The Theodore Boone book series by John Grisham takes place in the fictional town of Strattenburg, Pennsylvania. Is Strattenburg, Pennsylvania based on a real town?
I couldn't find any evidence supporting the fact that Grisham based Strattenburg off of a real town instead of just a generic archetype of a small town. There's no canon evidence to support either side.
However, I was still curious to see if Strattenburg bore any striking resemblances to some real towns in Pennsylvania. I went ahead and used this information, which is part of an official educational activity worksheet that serves as a companion to the books. Therefore, I'm assuming the information stated there is accurate.
It states that:
Strattenburg, in Stratten County, is a medium-sized town of around 75,000 population. We aren’t told exactly where it is, although sometimes we are given a clue: for example, in The Abduction it takes Theo and Ike six hours to drive from home to Chapel Hill, North Carolina. Also, we’re told that there is a river to the east of the town forming the border with the next county.
Using this Wikipedia article, only two Pennsylvania cities are close to the 75,000 mark stated in the worksheet: Bethlehem and Scranton. After narrowing it down to these two cities, I plugged both of them into Google Maps on a route to Chapel Hill. Bethlehem comes closest to the time stated, with an estimated time of arrival of 7 hours and 12 minutes, while a trip from Scranton is estimated to take 7 hours and 49 minutes.
Lastly, Bethlehem even has the river that is referenced in the worksheet: the Lehigh River, which runs in the eastern portion of Pennsylvania.
Thus, I think it's safe to say that although it's unknown whether Grisham based Strattenburg off of a real city, Bethlehem seems strikingly similar to Strattenburg if he did base it off of a real city.