AA 861 then UA 3907 at O'Hare
Hartford → Chicago → Washington
Timetable, Chicago time
14:20AA 861 from Hartford at the gate
12:00UA 3907 to Washington leaves the gate
21 h 40 apart on the timetable, overnight
UA 3907 leaves 21 h 40 after AA 861 arrives on the timetable: more than half a day, so not a connection we count.