AA 642 then UA 5725 at O'Hare
Dallas-Fort Worth → Chicago → South Bend
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
12:52UA 5725 to South Bend leaves the gate
23 h 42 apart on the timetable, overnight
UA 5725 leaves 23 h 42 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.