AA 642 then UA 3575 at O'Hare
Dallas-Fort Worth → Chicago → Montréal
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
10:37UA 3575 to Montréal leaves the gate
21 h 27 apart on the timetable, overnight
UA 3575 leaves 21 h 27 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.