AA 4557 then UA 324 at Atlanta
New York LaGuardia → Atlanta → Chicago O'Hare
Timetable, Atlanta time
09:09AA 4557 from New York LaGuardia at the gate
22:00UA 324 to Chicago O'Hare leaves the gate
12 h 51 apart on the timetable
UA 324 leaves 12 h 51 after AA 4557 arrives on the timetable: more than half a day, so not a connection we count.