AA 2998 then UA 3907 at O'Hare
Los Angeles → Chicago → Washington
Timetable, Chicago time
15:59AA 2998 from Los Angeles at the gate
12:00UA 3907 to Washington leaves the gate
20 h 01 apart on the timetable, overnight
UA 3907 leaves 20 h 01 after AA 2998 arrives on the timetable: more than half a day, so not a connection we count.