In Massachusetts, do the NPS touts at Lexington concord (if we still have a NPS?) and Old Ironsides. If you are in western Mass, old Sturbridge village is fun.
In NY, outside of city, consider Hyde Park for Roosevelt history plus there is a Dutch plantation house that is interesting for 17th century New York history.
In Maryland, consider old St Mary’s, which is really well done. The Baltimore train museum is also cool.
Of course there’s Getttysburg, you can do a horse or car tour of the battleground — we used a downloadable car tour. I also really liked this house tour:
https://www.shriverhouse.org/plan-your-visit/
In Florida, st Augustine is neat for Spanish American history plus a beach break. Also in Florida, I did this tour as a kid and it really stuck with me:
https://www.floridastateparks.org/parks-and-trails/marjorie-kinnan-rawlings-historic-state-park
Can you make it as far as New Orleans? There is so much cool history there—I would do:
WW2 museum
Tour of French quarter from the NPS
Tour of one of the plantations that includes a good discussion of life of enslaved people (there are a few that do this, rather than a home with the wind style tour)
Detroit is probably too far out of your way but this is another one that I remember really loving as a kid:
https://www.thehenryford.org/visit/greenfield-village/
I know you said not NY but the Tenement museum and Ellis island there are so great. I feel like there are a lot of sites focused on colonial history, and civil war history but very few focused on late 19th century and early 20th century through Great Depression.