During World War 2 black citizens served in every branch of the military, but the military was strictly segregated. Black men were put into units that consisted entirely of black men, but their officers were usually white, because the conventional wisdom of the time, even as late as the 1940's, was that black people couldn't do anything right unless they were led by white people. Nevertheless, thousands of black men in uniform distinguished themselves in the fight to the death against Fascism, which is itself nearly synonymous with Racism.
Also during World War 2, black citizens served in every war industry. Thousands flocked from south to north where the industries were and faithfully helped build the fabulous American war machine that did so much to defeat the Axis Powers. This experience also changed the black citizen and helped lead to the Civil Rights Movement.
But in 1945 once the war ended, and an economic recession began. War industries downsized and returned to peacetime pursuits, or disappeared altogether. At the same time tens of thousands of white soldiers returned from the battlefronts looking for jobs. Blacks, even black veterans were immediately displaced, but with no jobs they had nowhere to go. They couldn't return to the south where many had come from. There were even fewer jobs there. So they stayed where they were, in crowded black ghettos, where they made their way as best they could while crime and violence tended to rise, and the northern white population lifted its collective nose and sneered, "Typical." Once the war ended this was when black American’s became less progressive, as jobs were mostly given to whites and if given to a black it would help the employer. If a Black got a job the income for