DL 5813 then AA 1239 at Boston
Baltimore → Boston → Chicago O'Hare
Timetable, Boston time
09:07DL 5813 from Baltimore at the gate
08:16AA 1239 to Chicago O'Hare leaves the gate
23 h 09 apart on the timetable, overnight
AA 1239 leaves 23 h 09 after DL 5813 arrives on the timetable: more than half a day, so not a connection we count.