UA 3905 then AA 5281 at Houston
Cancún → Houston → Washington National
Timetable, Houston time
13:29UA 3905 from Cancún at the gate
07:00AA 5281 to Washington National leaves the gate
17 h 31 apart on the timetable, overnight
AA 5281 leaves 17 h 31 after UA 3905 arrives on the timetable: more than half a day, so not a connection we count.