AA 1997 then UA 4752 at O'Hare
St Louis → Chicago → Madison
Timetable, Chicago time
09:00AA 1997 from St Louis at the gate
16:40UA 4752 to Madison leaves the gate
7 h 40 apart on the timetable
The last days
AA 1997 and UA 4752 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.