In and around the Boston area like I have found in Pittsburgh campgrounds are few and far between. For the Boston area I would recommend Normandy Farms its really not in Boston but have found it to be well kept and a good place.
If retired military or civil service don't forget the FamCamps at Hanscom and they have an annex close to the cape.
Would help if we knew what route you are taking to help you out with the rest. I'm familiar with Baltimore and the area in and around the "school for wayward boy's and girls" in Annapolis.