Very new to the party but thought I'd post a suggestions for others who may be "lurking" for ideas.
Over the last several years my daughters and I have been on a quest to visit all of the 50 states and sometimes we find it hard to plan new and interesting things to do along the way. Not sure how, but we discovered a web resource called Atlas Obscura. By just "googling" the name of the area your in followed by "obscura" reveals historic, coo, odd and unusual things can be found in a particular place. The info pops up as a list and there's a map link so you can find things that are along the route you're taking or the area you might be staying in.
For example, just a few weeks ago we searched "South Carolina obscura" while planning a trip through Savannah and Charleston area and the kids discovered the Kazoo Factory and Museum in Beaufort. So off we went to see kazoos.... Yes it was smaller than we expected, and corny, but we had a great time learning a little history how Kazoo's are made and everybody got to build their own souvenir. Noisy for sure....
I just searched "Post Texas" and found the American Wind Power Center in nearby Lubbock that has, what appears to be, a pretty interesting collection of windmills. Again, not something I'd drive across Texas to see, but certainly worth an hour long rest stop if I was traveling thought the area.
Looking back we've seen some crazy interesting things like the world's largest fork, the largest collection of marbles, Atlanta's tiny doors, horses on the beach, 200 year old cannon balls in the side of buildings, many natural and man-made bridges and more than a few battlefields. We've seen little isty bits of history and places where big and important things took place.
Searching "____ Obscura" for towns and cities near where we live has also opened up a whole new list of things to do locally and when we have visitors from out of town.
Good luck to all as you discover the big, and little, things that make America a wonderful place to see.