UA 4458 then UA 5539 at O'Hare
Roanoke → Chicago → Cleveland
Timetable, Chicago time
19:00UA 4458 from Roanoke at the gate
10:50UA 5539 to Cleveland leaves the gate
15 h 50 apart on the timetable, overnight
UA 5539 leaves 15 h 50 after UA 4458 arrives on the timetable: more than half a day, so not a connection we count.