AA 642 then UA 1879 at O'Hare
Dallas-Fort Worth → Chicago → San Jose del Cabo
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
09:03UA 1879 to San Jose del Cabo leaves the gate
19 h 53 apart on the timetable, overnight
UA 1879 leaves 19 h 53 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.