AA 4518 then UA 3916 at O'Hare
Memphis → Chicago → New Orleans
Timetable, Chicago time
12:40AA 4518 from Memphis at the gate
07:00UA 3916 to New Orleans leaves the gate
18 h 20 apart on the timetable, overnight
UA 3916 leaves 18 h 20 after AA 4518 arrives on the timetable: more than half a day, so not a connection we count.