B6 1554 then DL 5679 at Boston
Washington National → Boston → Louisville
Timetable, Boston time
13:34B6 1554 from Washington National at the gate
09:55DL 5679 to Louisville leaves the gate
20 h 21 apart on the timetable, overnight
DL 5679 leaves 20 h 21 after B6 1554 arrives on the timetable: more than half a day, so not a connection we count.