DL 5619 then DL 1599 at Boston
Milwaukee → Boston → Washington National
Timetable, Boston time
22:02DL 5619 from Milwaukee at the gate
20:05DL 1599 to Washington National leaves the gate
22 h 03 apart on the timetable, overnight
DL 1599 leaves 22 h 03 after DL 5619 arrives on the timetable: more than half a day, so not a connection we count.