AA 9928 then UA 658 at O'Hare
New York LaGuardia → Chicago → Las Vegas
Timetable, Chicago time
06:45AA 9928 from New York LaGuardia at the gate
20:19UA 658 to Las Vegas leaves the gate
13 h 34 apart on the timetable
UA 658 leaves 13 h 34 after AA 9928 arrives on the timetable: more than half a day, so not a connection we count.