AA 2748 then UA 6074 at O'Hare
Las Vegas → Chicago → Clarksburg
Timetable, Chicago time
20:07AA 2748 from Las Vegas at the gate
19:50UA 6074 to Clarksburg leaves the gate
23 h 43 apart on the timetable, overnight
UA 6074 leaves 23 h 43 after AA 2748 arrives on the timetable: more than half a day, so not a connection we count.