AA 2447 then DL 2804 at Boston
Washington National → Boston → Chicago O'Hare
Timetable, Boston time
08:39AA 2447 from Washington National at the gate
20:55DL 2804 to Chicago O'Hare leaves the gate
12 h 16 apart on the timetable
DL 2804 leaves 12 h 16 after AA 2447 arrives on the timetable: more than half a day, so not a connection we count.