AA 764 then UA 3872 at O'Hare
Houston → Chicago → LCQ
Timetable, Chicago time
11:58AA 764 from Houston at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 33 apart on the timetable, overnight
UA 3872 leaves 12 h 33 after AA 764 arrives on the timetable: more than half a day, so not a connection we count.