AA 428 then UA 3914 at O'Hare
Portland (Oregon) → Chicago → Houston
Timetable, Chicago time
05:07AA 428 from Portland (Oregon) at the gate
20:30UA 3914 to Houston leaves the gate
15 h 23 apart on the timetable
UA 3914 leaves 15 h 23 after AA 428 arrives on the timetable: more than half a day, so not a connection we count.