AA 4504 then UA 5747 at O'Hare
South Bend → Chicago → Omaha
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
17:45UA 5747 to Omaha leaves the gate
23 h 10 apart on the timetable, overnight
UA 5747 leaves 23 h 10 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.