UA 3874 then AA 3316 at O'Hare
Chicago → Chicago → Los Angeles
Timetable, Chicago time
01:21UA 3874 from Chicago at the gate
15:25AA 3316 to Los Angeles leaves the gate
14 h 04 apart on the timetable
AA 3316 leaves 14 h 04 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.