This is a myth that was effectively quashed back when Civil War veterans were still alive to refute it. The only reason it exists now is probably because the racists behind its propagation are hoping that no one will do any fact checking.

The truth of the matter is, while Gen. Robert E. Lee had for months asked that the Confederacy be allowed to force black slaves to fight alongside white rebels, the Congress of the Confederacy, facing vehement opposition from slave owners, only approved the idea in March 28, 1865 -- a bare two weeks before the end of the war and far too late to be implemented.

As the magazine Confederate Veteran said in a June 1915 article: "If there were any such troops enlisted, there is no official record of same. For two reasons the act was never accomplished: First, the experiment was tried too late in the game, secondly, the owners of the slaves were reluctant to part with their property."