I saw your photos of the Carswell Air Show on your Flickr page. If you're interested in military aviation, the National Museum of the USAF is up at Wright-Patterson AFB in Dayton, about an hour and a half up I-75 from Cincinnati. I've not been there, but my daughter did it a few years ago and said it is pretty impressive.
National Museum of the USAF - Home
Are you driving up there from Texas? If so, and if you are into baseball, the Louisville Slugger Museum and Factory is on the way. There is a tour of the factory where you can see how they make the bats from start to finish. If you have any kids or grandkids who play, you can buy a personalized bat for them, which is kinda a unique gift.
Louisville Slugger Museum & Factory - Home Page - Home Page Main Content
Churchill Downs is also in Louisville, of course. There is no racing in September, but you can tour the track, if that's something that would interest you. It's kinda like going to Wrigley Field or Fenway Park, I guess.