AA 2578 then K4 221 at O'Hare
Boston → Chicago → Cincinnati Northern Kentucky
Timetable, Chicago time
17:36AA 2578 from Boston at the gate
16:20K4 221 to Cincinnati Northern Kentucky leaves the gate
22 h 44 apart on the timetable, overnight
K4 221 leaves 22 h 44 after AA 2578 arrives on the timetable: more than half a day, so not a connection we count.