AA 3258 then UA 654 at Houston
Miami → Houston → Washington National
Timetable, Houston time
09:00AA 3258 from Miami at the gate
12:07UA 654 to Washington National leaves the gate
3 h 07 apart on the timetable
The last days
AA 3258 and UA 654 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.