AA 642 then UA 4445 at O'Hare
Dallas-Fort Worth → Chicago → Birmingham (Alabama)
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
10:29UA 4445 to Birmingham (Alabama) leaves the gate
21 h 19 apart on the timetable, overnight
UA 4445 leaves 21 h 19 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.