AA 4394 then DL 5851 at Boston
New York LaGuardia → Boston → Baltimore
Timetable, Boston time
09:07AA 4394 from New York LaGuardia at the gate
21:15DL 5851 to Baltimore leaves the gate
12 h 08 apart on the timetable
DL 5851 leaves 12 h 08 after AA 4394 arrives on the timetable: more than half a day, so not a connection we count.