AA 1799 then UA 6060 at O'Hare
Cancún → Chicago → Lancaster
Timetable, Chicago time
19:20AA 1799 from Cancún at the gate
16:55UA 6060 to Lancaster leaves the gate
21 h 35 apart on the timetable, overnight
UA 6060 leaves 21 h 35 after AA 1799 arrives on the timetable: more than half a day, so not a connection we count.