Lyndon Johnson signing Executive Order 11246 couldnt erase bigotry, so Blacks have had to be more than exceptional to even be considered hireable.
Even in 2015, this often means being the only Black person in a department, or even a whole company. Its a tough climate to work in as business culture is foundationally White and male. What is acceptable and expected are based on the principles of a single gender and race.
Its why we still have Affirmative Action, Equal Opportunity Employer badges, and continuous debate over equal pay for minorities and women. If youre a Black woman
well, youd better be Oprah  not Oprah-like, actually be Oprah. And dont put Oprah on your resume.