AA 9866 then UA 4409 at O'Hare
Marquette → Chicago → Madison
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
08:41UA 4409 to Madison leaves the gate
22 h 11 apart on the timetable, overnight
UA 4409 leaves 22 h 11 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.