UA 3910 then AA 2667 at Houston
Washington → Houston → Philadelphia
Timetable, Houston time
14:30UA 3910 from Washington at the gate
12:46AA 2667 to Philadelphia leaves the gate
22 h 16 apart on the timetable, overnight
AA 2667 leaves 22 h 16 after UA 3910 arrives on the timetable: more than half a day, so not a connection we count.