UA 539 then AA 391 at DFW
Chicago O'Hare → Dallas-Fort Worth → Fort Myers
Timetable, Dallas-Fort Worth time
09:40UA 539 from Chicago O'Hare at the gate
09:05AA 391 to Fort Myers leaves the gate
23 h 25 apart on the timetable, overnight
AA 391 leaves 23 h 25 after UA 539 arrives on the timetable: more than half a day, so not a connection we count.