UA 6251 then DL 2709 at Houston
Detroit → Houston → Atlanta
Timetable, Houston time
13:21UA 6251 from Detroit at the gate
08:05DL 2709 to Atlanta leaves the gate
18 h 44 apart on the timetable, overnight
DL 2709 leaves 18 h 44 after UA 6251 arrives on the timetable: more than half a day, so not a connection we count.