AA 3549 then UA 3872 at O'Hare
Fort Wayne → Chicago → LCQ
Timetable, Chicago time
11:54AA 3549 from Fort Wayne at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 37 apart on the timetable, overnight
UA 3872 leaves 12 h 37 after AA 3549 arrives on the timetable: more than half a day, so not a connection we count.