AA 4455 then UA 2229 at Boston
Washington National → Boston → Chicago O'Hare
Timetable, Boston time
07:46AA 4455 from Washington National at the gate
20:25UA 2229 to Chicago O'Hare leaves the gate
12 h 39 apart on the timetable
UA 2229 leaves 12 h 39 after AA 4455 arrives on the timetable: more than half a day, so not a connection we count.