UA 3874 then AA 2769 at O'Hare
Chicago Rockford → Chicago → Washington National
Timetable, Chicago time
01:21UA 3874 from Chicago Rockford at the gate
16:51AA 2769 to Washington National leaves the gate
15 h 30 apart on the timetable
AA 2769 leaves 15 h 30 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.