AS 2170 then AA 2398 at Seattle
Redmond → Seattle → Chicago O'Hare
Timetable, Seattle time
07:13AS 2170 from Redmond at the gate
15:10AA 2398 to Chicago O'Hare leaves the gate
7 h 57 apart on the timetable
Seattle’s board gives a departure time for only about 56% of its flights, so many days show no gate time.
The last days
AS 2170 and AA 2398 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.