AA 1618 then K4 221 at O'Hare
Dallas-Fort Worth → Chicago → Cincinnati Northern Kentucky
Timetable, Chicago time
15:19AA 1618 from Dallas-Fort Worth at the gate
10:35K4 221 to Cincinnati Northern Kentucky leaves the gate
19 h 16 apart on the timetable, overnight
K4 221 leaves 19 h 16 after AA 1618 arrives on the timetable: more than half a day, so not a connection we count.