AA 504 then AA 1353 at O'Hare
New York LaGuardia → Chicago → Las Vegas
Timetable, Chicago time
13:19AA 504 from New York LaGuardia at the gate
16:59AA 1353 to Las Vegas leaves the gate
3 h 40 apart on the timetable
The last days
AA 504 and AA 1353 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.