AA 4504 then UA 2440 at O'Hare
South Bend → Chicago → Detroit
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
17:59UA 2440 to Detroit leaves the gate
23 h 24 apart on the timetable, overnight
UA 2440 leaves 23 h 24 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.