Thanks. If we check bags and get all our boarding passes in Atlanta when we check in with AA, would we have to check in again with QR at T5 or could we just hop off the train and go through security?
If you have a boarding pass you should be able to get through security. You still may have to get a QR issued pass at the gate. But since I never connect at ORD, hopefully someone else can jump in to give you an informed answer.