DL 5604 then AA 4448 at Boston
Memphis → Boston → New York JFK
Timetable, Boston time
13:35DL 5604 from Memphis at the gate
12:45AA 4448 to New York JFK leaves the gate
23 h 10 apart on the timetable, overnight
AA 4448 leaves 23 h 10 after DL 5604 arrives on the timetable: more than half a day, so not a connection we count.