Oh, and if you can't really "stop" in a particular state try looking for a great place to eat that's close to your route. My DS likes watching those crazy TV eating shows like Man Vs. Food, etc. So we stopped at Big Texan Steakhouse in Amarillo and saw someone trying the food challenge. Also stopped at Cadillac Ranch to spray paint some cars.
So we only did 2 quick things in TX and most people would saw we missed ALL the good stuff.... but we knew that going into the trip. There was no way we could do anymore in our timeframe. So we met people from Texas and saw how friendly they are. We saw some parts of the state as we passed through and saw how it differed from the northeast. Now we know hat we want to go back and explore more.
Same thing in Missouri. We were just passing through on our way home, but we stopped at Lambert's Restaurant - home of the "Thrown roll". Made a good stop and we have a photo in the album and we are all smiling. Sometimes a quick memory is better than nothing a all.