AA 818 then UA 3907 at O'Hare
Charlotte → Chicago → Washington
Timetable, Chicago time
12:22AA 818 from Charlotte at the gate
12:00UA 3907 to Washington leaves the gate
23 h 38 apart on the timetable, overnight
UA 3907 leaves 23 h 38 after AA 818 arrives on the timetable: more than half a day, so not a connection we count.