UA 3874 then AA 4527 at O'Hare
Chicago Rockford → Chicago → Baltimore
Timetable, Chicago time
01:21UA 3874 from Chicago Rockford at the gate
14:50AA 4527 to Baltimore leaves the gate
13 h 29 apart on the timetable
AA 4527 leaves 13 h 29 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.