AA 6488 then UA 4772 at O'Hare
Toronto Pearson → Chicago → Columbia Regional
Timetable, Chicago time
13:01AA 6488 from Toronto Pearson at the gate
12:45UA 4772 to Columbia Regional leaves the gate
23 h 44 apart on the timetable, overnight
UA 4772 leaves 23 h 44 after AA 6488 arrives on the timetable: more than half a day, so not a connection we count.