UA 5192 then AA 3484 at O'Hare
Jacksonville → Chicago → St Louis
Timetable, Chicago time
17:30UA 5192 from Jacksonville at the gate
09:30AA 3484 to St Louis leaves the gate
16 h apart on the timetable, overnight
AA 3484 leaves 16 h after UA 5192 arrives on the timetable: more than half a day, so not a connection we count.