AA 4504 then UA 1840 at O'Hare
South Bend → Chicago → Hartford
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
14:36UA 1840 to Hartford leaves the gate
20 h 01 apart on the timetable, overnight
UA 1840 leaves 20 h 01 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.