UA 6239 then AA 2131 at Charlotte
Washington → Charlotte → Saint Martin
Timetable, Charlotte time
14:22UA 6239 from Washington at the gate
08:27AA 2131 to Saint Martin leaves the gate
18 h 05 apart on the timetable, overnight
AA 2131 leaves 18 h 05 after UA 6239 arrives on the timetable: more than half a day, so not a connection we count.