UA 3874 then AA 3522 at O'Hare
Chicago Rockford → Chicago → Greenville-Spartanburg
Timetable, Chicago time
01:21UA 3874 from Chicago Rockford at the gate
15:06AA 3522 to Greenville-Spartanburg leaves the gate
13 h 45 apart on the timetable
AA 3522 leaves 13 h 45 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.