the Shelburne Museum just outside Burlington. Incredible place too hard to describe (light house, round Shaker barn & steam boat + in a huge park). Vermont Teddy Factory is just up the road too. Also took tram at Stowe ski resort which was cool to see leaves. VonTrapp resort has a tour of maple grove and syrup sugar house which was super interesting. Always fun to tour Ben & Jerry's there too. It's a fun trip but beware of the tourists right now. We went the last week in Sept so they weren't too bad yet but the leaves weren't quite at peak either.
If doing a road trip & depending on route, we stopped at Sharon visitor center which was really great. Also Woodstock, the Little Women house and Minute Man Natl Park would satisfy your history buff needs. We drove up from Providence so were able to stop at all these places and a few more I'm probably leaving out.