Green’s Dictionary of Slang

nigger-driver n.

also darkey-driver
[fig. use of nigger n.1 (1)]

[mid-19C–1940s] an employer who works his men excessively hard; used orig. of white slavemasters; also attrib.

In derivatives

nigger-driving (n.) [mid-19C+] (orig. US black)

1. the working of blacks to exhaustion by white bosses, also attrib.

2. any boss-employee relationship characterized by poor treatment.

nigger-driving (adj.)

[mid-19C–1900s] highly exploitative; also as v. nigger-drive (see cite 1901).