Hartford and Minneapolis are about 1,055 miles apart by road. Split the difference and you arrive near Detroit, the city closest to the halfway point between them. That splits the trip almost evenly — about 11 hr 11 min from Hartford and 11 hr 22 min from Minneapolis.
Over this distance most people will fly rather than drive the whole way. Detroit still makes a fair, central place for Hartford and Minneapolis to converge, splitting the travel instead of asking one side to cross the country.
If Detroit doesn't have what you're after, Cleveland and Buffalo are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Hartford and Minneapolis.
City descriptions adapted from Wikipedia (CC BY-SA); photos via Wikimedia Commons, credited above.