AA 3165 then UA 3376 at O'Hare
Phoenix → Chicago → St Louis
Timetable, Chicago time
17:55AA 3165 from Phoenix at the gate
11:00UA 3376 to St Louis leaves the gate
17 h 05 apart on the timetable, overnight
UA 3376 leaves 17 h 05 after AA 3165 arrives on the timetable: more than half a day, so not a connection we count.