AA 9866 then UA 4512 at O'Hare
Marquette → Chicago → Little Rock
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
08:45UA 4512 to Little Rock leaves the gate
22 h 15 apart on the timetable, overnight
UA 4512 leaves 22 h 15 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.