UA 262 then DL 2398 at Atlanta
Houston → Atlanta → Baltimore
Timetable, Atlanta time
21:11UA 262 from Houston at the gate
15:16DL 2398 to Baltimore leaves the gate
18 h 05 apart on the timetable, overnight
DL 2398 leaves 18 h 05 after UA 262 arrives on the timetable: more than half a day, so not a connection we count.