AA 4121 then UA 1525 at O'Hare
Green Bay → Chicago → Las Vegas
Timetable, Chicago time
07:27AA 4121 from Green Bay at the gate
15:06UA 1525 to Las Vegas leaves the gate
7 h 39 apart on the timetable
The last days
AA 4121 and UA 1525 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.