Not sure what the context is, but there was always a nontrivial black middle class. They were just segregated. One big problem with integration was the demise and disintegration of black communities as the black professional middle class moved out to pursue the "american dream".
As to Jordan's point about the attack on government and government/military being a big source of stable black middle class employment: ding ding ding. the attack on "big government" is a code for a racist attack on what's perceived as a jobs program for blacks and people of color more generally.