UA 1285 then K4 538 at O'Hare
Columbus (Ohio) → Chicago → Seoul
Timetable, Chicago time
07:34UA 1285 from Columbus (Ohio) at the gate
01:45K4 538 to Seoul leaves the gate
18 h 11 apart on the timetable, overnight
K4 538 leaves 18 h 11 after UA 1285 arrives on the timetable: more than half a day, so not a connection we count.