UA 6104 then AA 3111 at O'Hare
South Bend → Chicago → St Louis
Timetable, Chicago time
19:00UA 6104 from South Bend at the gate
09:30AA 3111 to St Louis leaves the gate
14 h 30 apart on the timetable, overnight
AA 3111 leaves 14 h 30 after UA 6104 arrives on the timetable: more than half a day, so not a connection we count.