AA 2491 then UA 1862 at O'Hare
Miami → Chicago → Punta Cana
Timetable, Chicago time
07:47AA 2491 from Miami at the gate
07:38UA 1862 to Punta Cana leaves the gate
23 h 51 apart on the timetable, overnight
UA 1862 leaves 23 h 51 after AA 2491 arrives on the timetable: more than half a day, so not a connection we count.