UA 3532 then AA 4442 at O'Hare
Knoxville → Chicago → Madison
Timetable, Chicago time
18:43UA 3532 from Knoxville at the gate
13:25AA 4442 to Madison leaves the gate
18 h 42 apart on the timetable, overnight
AA 4442 leaves 18 h 42 after UA 3532 arrives on the timetable: more than half a day, so not a connection we count.