AA 3564 then UA 3376 at O'Hare
Roanoke → Chicago → St Louis
Timetable, Chicago time
18:20AA 3564 from Roanoke at the gate
11:00UA 3376 to St Louis leaves the gate
16 h 40 apart on the timetable, overnight
UA 3376 leaves 16 h 40 after AA 3564 arrives on the timetable: more than half a day, so not a connection we count.