UA 4381 then AA 529 at O'Hare
Buffalo → Chicago → Knoxville
Timetable, Chicago time
14:55UA 4381 from Buffalo at the gate
10:36AA 529 to Knoxville leaves the gate
19 h 41 apart on the timetable, overnight
AA 529 leaves 19 h 41 after UA 4381 arrives on the timetable: more than half a day, so not a connection we count.