AA 9866 then DL 1578 at O'Hare
Marquette → Chicago → Minneapolis
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
09:59DL 1578 to Minneapolis leaves the gate
23 h 29 apart on the timetable, overnight
DL 1578 leaves 23 h 29 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.