AA 4504 then UA 622 at O'Hare
South Bend → Chicago → Austin
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
12:59UA 622 to Austin leaves the gate
18 h 24 apart on the timetable, overnight
UA 622 leaves 18 h 24 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.