AA 642 then UA 1972 at O'Hare
Dallas-Fort Worth → Chicago → San Antonio
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
09:00UA 1972 to San Antonio leaves the gate
19 h 50 apart on the timetable, overnight
UA 1972 leaves 19 h 50 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.