AA 214 then UA 3872 at O'Hare
Dallas-Fort Worth → Chicago → LCQ
Timetable, Chicago time
12:24AA 214 from Dallas-Fort Worth at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 07 apart on the timetable, overnight
UA 3872 leaves 12 h 07 after AA 214 arrives on the timetable: more than half a day, so not a connection we count.