KE 91 then DL 5622 at Boston
Seoul → Boston → Richmond
Timetable, Boston time
08:50KE 91 from Seoul at the gate
08:47DL 5622 to Richmond leaves the gate
23 h 57 apart on the timetable, overnight
DL 5622 leaves 23 h 57 after KE 91 arrives on the timetable: more than half a day, so not a connection we count.