AA 363 then AA 2553 at O'Hare
St Louis → Chicago → Miami
Timetable, Chicago time
06:29AA 363 from St Louis at the gate
16:31AA 2553 to Miami leaves the gate
10 h 02 apart on the timetable
The last days
AA 363 and AA 2553 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.