AA 3734 then UA 3876 at O'Hare
Lansing → Chicago → Miami
Timetable, Chicago time
06:05AA 3734 from Lansing at the gate
21:00UA 3876 to Miami leaves the gate
14 h 55 apart on the timetable
UA 3876 leaves 14 h 55 after AA 3734 arrives on the timetable: more than half a day, so not a connection we count.