UA 3910 then AA 1426 at Houston
Washington → Houston → Dallas-Fort Worth
Timetable, Houston time
14:30UA 3910 from Washington at the gate
12:13AA 1426 to Dallas-Fort Worth leaves the gate
21 h 43 apart on the timetable, overnight
AA 1426 leaves 21 h 43 after UA 3910 arrives on the timetable: more than half a day, so not a connection we count.