UA 3236 then AA 4778 at Houston
Mc Allen → Houston → Philadelphia
Timetable, Houston time
20:10UA 3236 from Mc Allen at the gate
14:25AA 4778 to Philadelphia leaves the gate
18 h 15 apart on the timetable, overnight
AA 4778 leaves 18 h 15 after UA 3236 arrives on the timetable: more than half a day, so not a connection we count.