AA 4504 then UA 1834 at O'Hare
South Bend → Chicago → Tampa
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
11:05UA 1834 to Tampa leaves the gate
16 h 30 apart on the timetable, overnight
UA 1834 leaves 16 h 30 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.