UA 3874 then AA 4294 at O'Hare
Chicago Rockford → Chicago → White Plains
Timetable, Chicago time
01:21UA 3874 from Chicago Rockford at the gate
14:02AA 4294 to White Plains leaves the gate
12 h 41 apart on the timetable
AA 4294 leaves 12 h 41 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.