You'll be in Rogers' Rangers country. I hope you read up about them before they go. Also read up on the French & Indian War (or at least get Chapter 1 of my book).
There are several French & Indian War forts in the area. In Charleston, New Hampshire, is Fort No. 4. After the St. Francis Raid, Rogers' Rangers reached that fort where they rested.
Fort William Henry. It's a recreation of the original log fort that is worth seeing. It's south of Ft. Ticonderoga.
Fort Carillon. It's further up the lake from Fort Ticonderoga. The French abandoned it and blew it up.
Bennington in New York State. Battlefield where Gen. John Stark and a bunch of farmers defeated some German regulars who were foraging and on a horse raiding mission for Burgyonne. It was a prong of Burgoynne's attack that was nipped in the bud, depleting his force.
If you visit New York, also see:
Fort Stanwick. Fort Stanwick was held by Americans and one of Burgoynne's column attacked that in a flanking motion meant to secure Burgoynne's flank and to divide the rebel forces. There was an unsuccessful siege of the fort and the British retreated.
Oriskany Battlefield. Just south of Fort Stanwick. Walk the trail and through the ambush site at the creek. The Indians had a good plan, but it was poorly executed because of the lack of fire discipline. The Americans found themselves surrounded but beat off the attack and the Indians suffered great losses. While the Indians were attacking at Oriskany, the Americans at Fort Stanwick sallied out and destroyed and looted the Indian camp. When the Indians returned from Oriskany, they were very demoralized and left, compelling the British to lift the siege.
Saratoga Battlefield. Burgoynne's slow column was checked by rebel forces and captured after two battles.
Albany - See the NY State Military Museum. Worth seeing. Don't forget the DE-238 USS Stewart. She's been restored and walking aboard her is like walking into a time capsule.
West Point Military Museum. Well worth seeing.
Remington - Go for the factory tour.
If passing through Massachusetts, go to Springfield:
1) Springfield Armory National Historic Monument. Make the pilgrimage. You must see it.
2) S&W Factory Tour
3) Indian Motor Cycle Museum (just a few blocks from the S&W Training Center/Museum
If in Hartford, CN, go to:
1) State Supreme Court Building/Capitol. They had the Colt collection there when I visited.