AA 3590 then UA 1862 at O'Hare
Nashville → Chicago → Punta Cana
Timetable, Chicago time
08:35AA 3590 from Nashville at the gate
07:38UA 1862 to Punta Cana leaves the gate
23 h 03 apart on the timetable, overnight
UA 1862 leaves 23 h 03 after AA 3590 arrives on the timetable: more than half a day, so not a connection we count.