You provide no dates or credible references for your assertions. Sorry, but I gotta go with the well documented histories and research of credible, unbiased Civil War historians, not to mention even some black descendants of those first celebrants in Charleston.

As for black people fighting on "both" sides during the war, pu-leeze! Black slaves were forced to fight by their "masters," for the most part. Sure, there may have been a minuscule number of black slaves who willingly fought to remain slaves, but they were so few in number that nobody reputable seems to be able to find their stories today.

This also feeds into the notion that black people also owned slaves -- a favorite trope of white racists today. Yeah, it's true. There were perhaps less than 50 black people who owned slaves on the scale that white planters did. But there were hundreds, if not more, "free" black people who owned their wives, husbands, and/or children in order to, and for the sole purpose of, keeping them out of the clutches of would-be (or former) white slaveholders.

Finally, there were far more than 500,000 soldiers killed outright. Some historians say as many as 750,000. That's not counting the almost one million slaves who died as a result of the many rampant and unchecked diseases unleashed by that war.