UA 751 then UA 8219 at San Francisco
Portland (Oregon) → San Francisco → Chicago O'Hare
Timetable, San Francisco time
15:15UA 751 from Portland (Oregon) at the gatealso CM 1419
18:10UA 8219 to Chicago O'Hare leaves the gate
2 h 55 apart on the timetable
The last days
UA 751 and UA 8219 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.