AA 572 then UA 4550 at O'Hare
Dallas-Fort Worth → Chicago → Columbia Regional
Timetable, Chicago time
20:00AA 572 from Dallas-Fort Worth at the gate
19:45UA 4550 to Columbia Regional leaves the gate
23 h 45 apart on the timetable, overnight
UA 4550 leaves 23 h 45 after AA 572 arrives on the timetable: more than half a day, so not a connection we count.