AA 4504 then UA 8284 at O'Hare
South Bend → Chicago → Santa Ana
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
17:59UA 8284 to Santa Ana leaves the gate
23 h 24 apart on the timetable, overnight
UA 8284 leaves 23 h 24 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.