AA 5589 then UA 3998 at Charlotte
Greenville-Spartanburg → Charlotte → Washington
Timetable, Charlotte time
07:45AA 5589 from Greenville-Spartanburg at the gate
19:55UA 3998 to Washington leaves the gate
12 h 10 apart on the timetable
UA 3998 leaves 12 h 10 after AA 5589 arrives on the timetable: more than half a day, so not a connection we count.