AA 4504 then UA 3575 at O'Hare
South Bend → Chicago → Montréal
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
10:37UA 3575 to Montréal leaves the gate
16 h 02 apart on the timetable, overnight
UA 3575 leaves 16 h 02 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.