UA 3532 then AA 1475 at O'Hare
Knoxville → Chicago → Las Vegas
Timetable, Chicago time
18:43UA 3532 from Knoxville at the gate
13:52AA 1475 to Las Vegas leaves the gate
19 h 09 apart on the timetable, overnight
AA 1475 leaves 19 h 09 after UA 3532 arrives on the timetable: more than half a day, so not a connection we count.