AA 2720 then K4 578 at O'Hare
Phoenix → Chicago → Seoul
Timetable, Chicago time
16:09AA 2720 from Phoenix at the gate
07:40K4 578 to Seoul leaves the gate
15 h 31 apart on the timetable, overnight
K4 578 leaves 15 h 31 after AA 2720 arrives on the timetable: more than half a day, so not a connection we count.