It would help if we knew where you were starting and what route you had in mind. ;D Let us know and we'll see what we can add. We used to live in CT and still visit in the summer. Not much there except along the shore for campgrounds. However there are some pretty areas in the state.
We'll be starting out at Latrobe, Pa. 50 mi east of Pittsburgh. Maybe that isn't the best place to go for a first time --it is just somewhere we've always wanted to go. Maybe you could make some suggestions in that area too.
By the way, I was referring to the traffic in Boston itself. It is a nightmare. To give you an idea, I routinely drive my trailer right thru the middle of Los Angeles from the coast to the other side of downtown LA. I even navigate the dreaded I-405 by LAX with it. I would not try that on a bet in Boston. Stay outside of the city itself and use other transportation to get in.
You will want to park outside Boston and take a car or train, if available, into the city. From what I remember there are quite a few one way streets and some very narrow ones. Normandy Farms is a popular campground outside Boston. Not sure of the exact distance. I see Black Bear campground advertises the commuter rail to Boston. It's in Salisbury, MA. Again I don't know how long it would take the train to get there.
If you are interested in history Sturbridge Village is probably on the way. It's at the junction of I-84 and I-90. It's a recreation of a 1700's village. Haven't been there in years but it was very well done. Guides in period dress staff many of the buildings and even do some of the work as it was done in those days.