Can I visit Chicago during a 5.5 hour layover in O'Hare?

I will be flying from Boston to Tokyo with a 5.5 hour morning layover in Chicago. I'm thinking of going out to the city for some late breakfast and/or sightseeing. I've never left an airport during a layover before, so I have some questions.I'll land in Chicago at 8am, and take off at 1:30pm.I imagine I'll leave the airport by 9, and should be back by 11:30. Is this reasonable?What's the best way to deal with luggage? I assume that I'll have to claim the luggage from the domestic flight, then re-check it for the international flight. Can I leav...Read more