Y4 700 then CV 251 at O'Hare
Mexico City → Chicago → Dallas-Fort Worth
Timetable, Chicago time
04:43Y4 700 from Mexico City at the gate
03:00CV 251 to Dallas-Fort Worth leaves the gate
22 h 17 apart on the timetable, overnight
CV 251 leaves 22 h 17 after Y4 700 arrives on the timetable: more than half a day, so not a connection we count.