AA 2453 then DL 5851 at Boston
Los Angeles → Boston → Baltimore
Timetable, Boston time
07:47AA 2453 from Los Angeles at the gate
21:15DL 5851 to Baltimore leaves the gate
13 h 28 apart on the timetable
DL 5851 leaves 13 h 28 after AA 2453 arrives on the timetable: more than half a day, so not a connection we count.