AA 1910 then UA 5191 at O'Hare
Cancún → Chicago → Lancaster
Timetable, Chicago time
16:29AA 1910 from Cancún at the gate
08:50UA 5191 to Lancaster leaves the gate
16 h 21 apart on the timetable, overnight
UA 5191 leaves 16 h 21 after AA 1910 arrives on the timetable: more than half a day, so not a connection we count.