UA 3911 then AA 555 at O'Hare
Portland (Oregon) → Chicago → Houston
Timetable, Chicago time
17:09UA 3911 from Portland (Oregon) at the gate
15:13AA 555 to Houston leaves the gate
22 h 04 apart on the timetable, overnight
AA 555 leaves 22 h 04 after UA 3911 arrives on the timetable: more than half a day, so not a connection we count.