AA 4504 then UA 729 at O'Hare
South Bend → Chicago → Philadelphia
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
08:50UA 729 to Philadelphia leaves the gate
14 h 15 apart on the timetable, overnight
UA 729 leaves 14 h 15 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.