AA 4504 then UA 2866 at O'Hare
South Bend → Chicago → San Francisco
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
16:35UA 2866 to San Francisco leaves the gate
22 h apart on the timetable, overnight
UA 2866 leaves 22 h after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.