AA 642 then UA 795 at O'Hare
Dallas-Fort Worth → Chicago → Vancouver
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
08:49UA 795 to Vancouver leaves the gate
19 h 39 apart on the timetable, overnight
UA 795 leaves 19 h 39 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.