AA 9866 then UA 795 at O'Hare
Marquette → Chicago → Vancouver
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
08:49UA 795 to Vancouver leaves the gate
22 h 19 apart on the timetable, overnight
UA 795 leaves 22 h 19 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.