AA 428 then UA 6105 at O'Hare
Portland (Oregon) → Chicago → YIP
Timetable, Chicago time
05:07AA 428 from Portland (Oregon) at the gate
17:30UA 6105 to YIP leaves the gate
12 h 23 apart on the timetable
UA 6105 leaves 12 h 23 after AA 428 arrives on the timetable: more than half a day, so not a connection we count.