AA 3580 then UA 8139 at O'Hare
Louisville → Chicago → Nashville
Timetable, Chicago time
13:30AA 3580 from Louisville at the gate
18:20UA 8139 to Nashville leaves the gate
4 h 50 apart on the timetable
The last days
AA 3580 and UA 8139 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.