AA 5510 then DL 490 at Atlanta
Washington National → Atlanta → New York LaGuardia
Timetable, Atlanta time
23:23AA 5510 from Washington National at the gate
20:30DL 490 to New York LaGuardia leaves the gate
21 h 07 apart on the timetable, overnight
DL 490 leaves 21 h 07 after AA 5510 arrives on the timetable: more than half a day, so not a connection we count.