UA 3532 then AA 4190 at O'Hare
Knoxville → Chicago → Roanoke
Timetable, Chicago time
18:43UA 3532 from Knoxville at the gate
13:23AA 4190 to Roanoke leaves the gate
18 h 40 apart on the timetable, overnight
AA 4190 leaves 18 h 40 after UA 3532 arrives on the timetable: more than half a day, so not a connection we count.