AA 4504 then UA 3702 at O'Hare
South Bend → Chicago → Indianapolis
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
12:45UA 3702 to Indianapolis leaves the gate
18 h 10 apart on the timetable, overnight
UA 3702 leaves 18 h 10 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.