AA 440 then AA 3484 at O'Hare
Houston → Chicago → St Louis
Timetable, Chicago time
14:29AA 440 from Houston at the gate
09:30AA 3484 to St Louis leaves the gate
19 h 01 apart on the timetable, overnight
AA 3484 leaves 19 h 01 after AA 440 arrives on the timetable: more than half a day, so not a connection we count.