AA 4504 then UA 9912 at O'Hare
South Bend → Chicago → Columbus (Ohio)
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
15:30UA 9912 to Columbus (Ohio) leaves the gate
20 h 55 apart on the timetable, overnight
UA 9912 leaves 20 h 55 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.