UA 503 then MQ 4262 at O'Hare
Boston → Chicago → Cincinnati Northern Kentucky
Timetable, Chicago time
12:48UA 503 from Boston at the gate
00:57MQ 4262 to Cincinnati Northern Kentucky leaves the gate
12 h 09 apart on the timetable, overnight
MQ 4262 leaves 12 h 09 after UA 503 arrives on the timetable: more than half a day, so not a connection we count.