If the opposition were to admit that blacks fought for the South, it would destroy their whole premise as to why the war was fought. 

There are numerous accounts of black participation in the battle of First Manassas in the summer of 1861. Black combatants shot, killed, and captured Union troops. Loyal slaves were said to have fought with outstanding bravery alongside their masters. These reports also provide testimony to the fidelity of black Rebels in combat. General Forrest had high praise for the black troops in his Cavalry Command. 

One black soldier was moving about the field when ordered to surrender by a Union officer. The Rebel replied, "No sir, you are my prisoner," while drawing a pistol and shooting the officer dead. He then secured the officer's sidearm and after the battle boasted loudly of having quieted at least one of "the stinkin' Yankees who cam here `specting to whip us Southerners." Another black Confederate who stood behind a tree allowed two Union soldiers to pass before shooting one in the shoulders, clubbing him with a pistol, while demanding the other to surrender. Both prisoners were marched into Confederate lines. 

An Alabama officer's servant marched a Zouave into camp proclaiming, "Massa, here one of dese devils who been shooting at us, Suh."

“There are at the present moment, many colored men in the Confederate Army doing duty not only as cooks, servants, and laborers, but as real soldiers, having muskets on their shoulders and bullets in their pockets, ready to shoot down loyal troops and do all that soldiers may do to destroy the Federal government and build up that of the traitors and rebels.” Black abolitionist Frederick Douglas 

Photo: South Carolina monument to faithful slaves...