DL 1634 then UA 3921 at O'Hare
Los Angeles → Chicago → Washington National
Timetable, Chicago time
23:47DL 1634 from Los Angeles at the gate
22:00UA 3921 to Washington National leaves the gate
22 h 13 apart on the timetable, overnight
UA 3921 leaves 22 h 13 after DL 1634 arrives on the timetable: more than half a day, so not a connection we count.