AA 542 then K4 221 at O'Hare
Washington National → Chicago → Cincinnati Northern Kentucky
Timetable, Chicago time
19:56AA 542 from Washington National at the gate
16:20K4 221 to Cincinnati Northern Kentucky leaves the gate
20 h 24 apart on the timetable, overnight
K4 221 leaves 20 h 24 after AA 542 arrives on the timetable: more than half a day, so not a connection we count.