AA 9866 then UA 751 at O'Hare
Marquette → Chicago → Portland (Oregon)
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
09:05UA 751 to Portland (Oregon) leaves the gate
22 h 35 apart on the timetable, overnight
UA 751 leaves 22 h 35 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.