CV 251 then AA 1907 at O'Hare
Anchorage → Chicago → Cancún
Timetable, Chicago time
19:00CV 251 from Anchorage at the gate
07:10AA 1907 to Cancún leaves the gate
12 h 10 apart on the timetable, overnight
AA 1907 leaves 12 h 10 after CV 251 arrives on the timetable: more than half a day, so not a connection we count.