AA 2564 then UA 3872 at O'Hare
Los Angeles → Chicago → LCQ
Timetable, Chicago time
12:21AA 2564 from Los Angeles at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 10 apart on the timetable, overnight
UA 3872 leaves 12 h 10 after AA 2564 arrives on the timetable: more than half a day, so not a connection we count.