UA 5191 then AA 1312 at O'Hare
South Bend → Chicago → Jacksonville
Timetable, Chicago time
07:25UA 5191 from South Bend at the gate
19:30AA 1312 to Jacksonville leaves the gate
12 h 05 apart on the timetable
AA 1312 leaves 12 h 05 after UA 5191 arrives on the timetable: more than half a day, so not a connection we count.