AA 3815 then UA 399 at O'Hare
Hartford → Chicago → Baltimore
Timetable, Chicago time
20:15AA 3815 from Hartford at the gate
16:05UA 399 to Baltimore leaves the gate
19 h 50 apart on the timetable, overnight
UA 399 leaves 19 h 50 after AA 3815 arrives on the timetable: more than half a day, so not a connection we count.