AA 947 then K4 578 at O'Hare
Boston → Chicago → Seoul
Timetable, Chicago time
09:30AA 947 from Boston at the gate
07:40K4 578 to Seoul leaves the gate
22 h 10 apart on the timetable, overnight
K4 578 leaves 22 h 10 after AA 947 arrives on the timetable: more than half a day, so not a connection we count.