AA 6326 then UA 3872 at O'Hare
Lexington → Chicago → LCQ
Timetable, Chicago time
12:14AA 6326 from Lexington at the gate
00:31UA 3872 to LCQ leaves the gate
12 h 17 apart on the timetable, overnight
UA 3872 leaves 12 h 17 after AA 6326 arrives on the timetable: more than half a day, so not a connection we count.