AC 8483 then UA 3376 at O'Hare
Montréal → Chicago → St Louis
Timetable, Chicago time
19:52AC 8483 from Montréal at the gate
11:00UA 3376 to St Louis leaves the gate
15 h 08 apart on the timetable, overnight
UA 3376 leaves 15 h 08 after AC 8483 arrives on the timetable: more than half a day, so not a connection we count.