AA 547 then UA 5191 at O'Hare
Boston → Chicago → Lancaster
Timetable, Chicago time
15:29AA 547 from Boston at the gate
08:50UA 5191 to Lancaster leaves the gate
17 h 21 apart on the timetable, overnight
UA 5191 leaves 17 h 21 after AA 547 arrives on the timetable: more than half a day, so not a connection we count.