AA 802 then AA 1779 at Boston
Chicago O'Hare → Boston → Washington National
Timetable, Boston time
12:07AA 802 from Chicago O'Hare at the gate
19:58AA 1779 to Washington National leaves the gate
7 h 51 apart on the timetable
Boston’s board gives an arrival time for only about 59% of its flights, so many days show no gate time.
The last days
AA 802 and AA 1779 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.