AA 5510 then DL 2987 at Atlanta
Washington National → Atlanta → Boston
Timetable, Atlanta time
23:23AA 5510 from Washington National at the gate
20:50DL 2987 to Boston leaves the gate
21 h 27 apart on the timetable, overnight
DL 2987 leaves 21 h 27 after AA 5510 arrives on the timetable: more than half a day, so not a connection we count.