AA 4504 then UA 8137 at O'Hare
South Bend → Chicago → Los Angeles
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
13:50UA 8137 to Los Angeles leaves the gate
19 h 15 apart on the timetable, overnight
UA 8137 leaves 19 h 15 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.