CV 251 then AA 4780 at O'Hare
Anchorage → Chicago → Buffalo
Timetable, Chicago time
19:00CV 251 from Anchorage at the gate
08:00AA 4780 to Buffalo leaves the gate
13 h apart on the timetable, overnight
AA 4780 leaves 13 h after CV 251 arrives on the timetable: more than half a day, so not a connection we count.