AA 1672 then UA 3907 at O'Hare
Harrisburg → Chicago → Washington
Timetable, Chicago time
13:29AA 1672 from Harrisburg at the gate
12:00UA 3907 to Washington leaves the gate
22 h 31 apart on the timetable, overnight
UA 3907 leaves 22 h 31 after AA 1672 arrives on the timetable: more than half a day, so not a connection we count.