UA 3874 then AA 3033 at O'Hare
Chicago Rockford → Chicago → Atlanta
Timetable, Chicago time
01:21UA 3874 from Chicago Rockford at the gate
15:09AA 3033 to Atlanta leaves the gate
13 h 48 apart on the timetable
AA 3033 leaves 13 h 48 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.