Welcome the the Cellar, and the USA, diminished.
Oh, and hi to Persistence, too.
As you enter each state you should see signs for "Welcome Centers". They usually have tons of free brochures on the attractions in that state.
Keep an eye out for signs and billboards advertising local things to see, too
How are you traveling? I assume you're driving or cycling, but staying in motels? hostels? camping? Ask the locals where you stay, what's interesting in the area.
Have fun and report back what you find, please.