AA 9866 then AA 6239 at O'Hare
Marquette → Chicago → Idaho Falls
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
10:29AA 6239 to Idaho Falls leaves the gate
23 h 59 apart on the timetable, overnight
AA 6239 leaves 23 h 59 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.