AA 3375 then AA 3484 at O'Hare
Fargo → Chicago → St Louis
Timetable, Chicago time
14:45AA 3375 from Fargo at the gate
09:30AA 3484 to St Louis leaves the gate
18 h 45 apart on the timetable, overnight
AA 3484 leaves 18 h 45 after AA 3375 arrives on the timetable: more than half a day, so not a connection we count.