AA 2903 then UA 5201 at O'Hare
Washington National → Chicago → Milwaukee
Timetable, Chicago time
07:26AA 2903 from Washington National at the gate
20:00UA 5201 to Milwaukee leaves the gate
12 h 34 apart on the timetable
UA 5201 leaves 12 h 34 after AA 2903 arrives on the timetable: more than half a day, so not a connection we count.