AA 9928 then UA 590 at O'Hare
New York LaGuardia → Chicago → Denver
Timetable, Chicago time
06:45AA 9928 from New York LaGuardia at the gate
21:47UA 590 to Denver leaves the gate
15 h 02 apart on the timetable
UA 590 leaves 15 h 02 after AA 9928 arrives on the timetable: more than half a day, so not a connection we count.