UA 511 then LF 7920 at O'Hare
Washington National → Chicago → BKX
Timetable, Chicago time
14:27UA 511 from Washington National at the gate
13:45LF 7920 to BKX leaves the gate
23 h 18 apart on the timetable, overnight
LF 7920 leaves 23 h 18 after UA 511 arrives on the timetable: more than half a day, so not a connection we count.