AA 4504 then UA 2809 at O'Hare
South Bend → Chicago → Dallas-Fort Worth
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
10:40UA 2809 to Dallas-Fort Worth leaves the gate
16 h 05 apart on the timetable, overnight
UA 2809 leaves 16 h 05 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.