Other Pieces of the Puzzle
OK - now I have a departure point, roughly Harrisburg. That always helps. The other things that will go into deciding where to stop are your interests and the actually time you have available. If I were making this trip, I'd stay south of the PA Turnpike by taking I-70 and US-40 west through Maryland with possible stops at Chesapeake and Ohio Canal National Historical Park, Fort Frederick State Park, Rocky Gap State Park or the future site of Noah's Ark. Then continue on US-40 across southwestern Pennsylvania seeing Fort Necessity (mentioned earlier) and on to Wheeling, WV. Once in Ohio, US-250 will take you into Ohio's Amish Country. In northwest Ohio, you have your choice of the Old Mill Stream Scenic Byway and/or the Lincoln Highway. Finally, US-30 would offer the most direct route up to Chicago to finish off your trip. This is, I believe, a 4-lane divided (but not controlled access) highway through woods and farming country for the most part. None of those roads or venues is going to be a major tourist attraction, but all will prove worthwhile.
AZBuck