AA 4504 then UA 2430 at O'Hare
South Bend → Chicago → Philadelphia
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
14:35UA 2430 to Philadelphia leaves the gate
20 h apart on the timetable, overnight
UA 2430 leaves 20 h after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.