AA 753 then AA 1457 at O'Hare
Philadelphia → Chicago → Boston
Timetable, Chicago time
19:30AA 753 from Philadelphia at the gate
20:00AA 1457 to Boston leaves the gate
30 min apart on the timetable
The last days
AA 753 and AA 1457 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.