UA 565 then AA 873 at O'Hare
Washington → Chicago → Atlanta
Timetable, Chicago time
07:29UA 565 from Washington at the gate
07:17AA 873 to Atlanta leaves the gate
23 h 48 apart on the timetable, overnight
AA 873 leaves 23 h 48 after UA 565 arrives on the timetable: more than half a day, so not a connection we count.