AA 6486 then UA 4502 at O'Hare
Detroit → Chicago → Chattanooga
Timetable, Chicago time
17:29AA 6486 from Detroit at the gate
14:29UA 4502 to Chattanooga leaves the gate
21 h apart on the timetable, overnight
UA 4502 leaves 21 h after AA 6486 arrives on the timetable: more than half a day, so not a connection we count.