AA 5477 then UA 3751 at O'Hare
Madison → Chicago → Washington
Timetable, Chicago time
08:50AA 5477 from Madison at the gate
15:37UA 3751 to Washington leaves the gate
6 h 47 apart on the timetable
The last days
AA 5477 and UA 3751 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.