AA 440 then AA 4459 at O'Hare
Houston → Chicago → Memphis
Timetable, Chicago time
14:29AA 440 from Houston at the gate
21:09AA 4459 to Memphis leaves the gate
6 h 40 apart on the timetable
The last days
AA 440 and AA 4459 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.