AA 9866 then AA 4919 at O'Hare
Marquette → Chicago → Milwaukee
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
10:05AA 4919 to Milwaukee leaves the gate
23 h 35 apart on the timetable, overnight
AA 4919 leaves 23 h 35 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.