AA 890 then UA 3872 at O'Hare
New York LaGuardia → Chicago → LCQ
Timetable, Chicago time
11:50AA 890 from New York LaGuardia at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 41 apart on the timetable, overnight
UA 3872 leaves 12 h 41 after AA 890 arrives on the timetable: more than half a day, so not a connection we count.