I estimate that 5,000 Blacks were attached to Robert E. Lee's Army of Northern Virginia (80,000 strong) during the Gettysburg invasion in the summer of 1863, representing about six percent of total Confederate manpower.

I have identified the occupation of 33 of the former number, whose principal duties were as follows:

Body Servant/Valet - 12
Cook - 7
Tended Horses - 5
Nurse - 2
Paper/Mail Carrier - 2
Driver/Teamster - 2
Forager - 2
Freeborn Laborer - 1