AA 3083 then UA 3907 at O'Hare
Los Angeles → Chicago → Washington
Timetable, Chicago time
17:00AA 3083 from Los Angeles at the gate
12:00UA 3907 to Washington leaves the gate
19 h apart on the timetable, overnight
UA 3907 leaves 19 h after AA 3083 arrives on the timetable: more than half a day, so not a connection we count.