UA 3851 then DL 2140 at Houston
Seoul → Houston → New York LaGuardia
Timetable, Houston time
17:54UA 3851 from Seoul at the gate
11:09DL 2140 to New York LaGuardia leaves the gate
17 h 15 apart on the timetable, overnight
DL 2140 leaves 17 h 15 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.