From Wikipedia

 Unforgivable Blackness

 John Arthur ("Jack") Johnson (March 31, 1878 – June 10, 1946), nicknamed the “Galveston Giant”, was an American boxer, the second African American Boxing Champion, and the first African American world heavyweight boxing champion (1908–1915).

 Johnson was born in Galveston, Texas, the third child and first son of Henry and Tina "Tiny" Johnson, former slaves who worked at blue-collar jobs to raise six children and taught them how to read and write. He dropped out of school after just five or six years of education to get a job as a dock worker in Galveston.