DL 5703 then UA 503 at Boston
Baltimore → Boston → Chicago O'Hare
Timetable, Boston time
10:41DL 5703 from Baltimore at the gate
10:25UA 503 to Chicago O'Hare leaves the gate
23 h 44 apart on the timetable, overnight
UA 503 leaves 23 h 44 after DL 5703 arrives on the timetable: more than half a day, so not a connection we count.