AA 2129 then AA 4599 at Philadelphia
Miami → Philadelphia → Boston
Timetable, Philadelphia time
09:45AA 2129 from Miami at the gate
14:10AA 4599 to Boston leaves the gate
4 h 25 apart on the timetable
The last days
AA 2129 and AA 4599 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.