AA 540 then AA 3484 at O'Hare
Nashville → Chicago → St Louis
Timetable, Chicago time
11:05AA 540 from Nashville at the gate
09:30AA 3484 to St Louis leaves the gate
22 h 25 apart on the timetable, overnight
AA 3484 leaves 22 h 25 after AA 540 arrives on the timetable: more than half a day, so not a connection we count.