Spartacus, this question has been a deep one. Why did the Allies, especially America, did not do anything to combat racism in their armies?

[NormanStewart]

Correct, it’s the Ku Klux Klan.

How did the Ku Klux Klan do in WW2 e.g. Robert Byrd

Actually, the Second Klan was in decline by 1941, though they were still active. The fallout from the Stephenson case in 1925 as well as widespread condemnation of their “gangsterism, floggings and racial and religious intolerance” by the media and the general public at large (my grandfather among them) pretty much ensured that, by the early 1930s, the Klan was discredited by all but the most ardent followers and sympathizers. A steep decline in membership followed – millions reduced to tens o…