AA 9781 then UA 2665 at Philadelphia
New York LaGuardia → Philadelphia → Chicago O'Hare
Timetable, Philadelphia time
06:00AA 9781 from New York LaGuardia at the gate
18:46UA 2665 to Chicago O'Hare leaves the gate
12 h 46 apart on the timetable
UA 2665 leaves 12 h 46 after AA 9781 arrives on the timetable: more than half a day, so not a connection we count.