AA 4504 then UA 1776 at O'Hare
South Bend → Chicago → Philadelphia
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
18:20UA 1776 to Philadelphia leaves the gate
23 h 45 apart on the timetable, overnight
UA 1776 leaves 23 h 45 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.