AA 1866 then AA 2880 at Philadelphia
Denver → Philadelphia → Chicago O'Hare
Timetable, Philadelphia time
05:35AA 1866 from Denver at the gate
15:48AA 2880 to Chicago O'Hare leaves the gate
10 h 13 apart on the timetable
The last days
AA 1866 and AA 2880 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.