UA 3911 then AA 3554 at O'Hare
Portland (Oregon) → Chicago → Jacksonville
Timetable, Chicago time
17:09UA 3911 from Portland (Oregon) at the gate
13:29AA 3554 to Jacksonville leaves the gate
20 h 20 apart on the timetable, overnight
AA 3554 leaves 20 h 20 after UA 3911 arrives on the timetable: more than half a day, so not a connection we count.