UA 1535 then AA 6238 at DFW
Houston → Dallas-Fort Worth → Amarillo
Timetable, Dallas-Fort Worth time
19:33UA 1535 from Houston at the gate
08:25AA 6238 to Amarillo leaves the gate
12 h 52 apart on the timetable, overnight
AA 6238 leaves 12 h 52 after UA 1535 arrives on the timetable: more than half a day, so not a connection we count.