DL 1007 then UA 324 at Atlanta
Washington National → Atlanta → Chicago O'Hare
Timetable, Atlanta time
21:41DL 1007 from Washington National at the gate
17:36UA 324 to Chicago O'Hare leaves the gate
19 h 55 apart on the timetable, overnight
UA 324 leaves 19 h 55 after DL 1007 arrives on the timetable: more than half a day, so not a connection we count.