AA 9950 then UA 359 at O'Hare
Philadelphia → Chicago → Mexico City
Timetable, Chicago time
13:49AA 9950 from Philadelphia at the gate
08:55UA 359 to Mexico City leaves the gate
19 h 06 apart on the timetable, overnight
UA 359 leaves 19 h 06 after AA 9950 arrives on the timetable: more than half a day, so not a connection we count.