AA 2146 then AA 1948 at O'Hare
Boston → Chicago → San Francisco
Timetable, Chicago time
08:00AA 2146 from Boston at the gate
10:30AA 1948 to San Francisco leaves the gate
2 h 30 apart on the timetable
The last days
AA 2146 and AA 1948 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.