AA 3695 then UA 3376 at O'Hare
Bismarck → Chicago → St Louis
Timetable, Chicago time
15:30AA 3695 from Bismarck at the gate
11:00UA 3376 to St Louis leaves the gate
19 h 30 apart on the timetable, overnight
UA 3376 leaves 19 h 30 after AA 3695 arrives on the timetable: more than half a day, so not a connection we count.