AA 3815 then UA 5869 at O'Hare
Hartford → Chicago → Sioux Falls
Timetable, Chicago time
20:15AA 3815 from Hartford at the gate
16:00UA 5869 to Sioux Falls leaves the gate
19 h 45 apart on the timetable, overnight
UA 5869 leaves 19 h 45 after AA 3815 arrives on the timetable: more than half a day, so not a connection we count.