UA 5193 then AA 6255 at O'Hare
Clarksburg → Chicago → Sioux Falls
Timetable, Chicago time
16:00UA 5193 from Clarksburg at the gate
12:59AA 6255 to Sioux Falls leaves the gate
20 h 59 apart on the timetable, overnight
AA 6255 leaves 20 h 59 after UA 5193 arrives on the timetable: more than half a day, so not a connection we count.