OO 225 then AA 2748 at O'Hare
Richmond → Chicago → Las Vegas
Timetable, Chicago time
11:48OO 225 from Richmond at the gate
11:00AA 2748 to Las Vegas leaves the gate
23 h 12 apart on the timetable, overnight
AA 2748 leaves 23 h 12 after OO 225 arrives on the timetable: more than half a day, so not a connection we count.