AA 5001 then UA 3376 at O'Hare
Birmingham (Alabama) → Chicago → St Louis
Timetable, Chicago time
15:35AA 5001 from Birmingham (Alabama) at the gate
11:00UA 3376 to St Louis leaves the gate
19 h 25 apart on the timetable, overnight
UA 3376 leaves 19 h 25 after AA 5001 arrives on the timetable: more than half a day, so not a connection we count.