AA 4570 then DL 5679 at Boston
Washington National → Boston → Louisville
Timetable, Boston time
14:43AA 4570 from Washington National at the gate
09:55DL 5679 to Louisville leaves the gate
19 h 12 apart on the timetable, overnight
DL 5679 leaves 19 h 12 after AA 4570 arrives on the timetable: more than half a day, so not a connection we count.