Racism was not what caused the Civil War. The issues that caused the Civil War not only still exist today — but were also a factor on Trump’s getting elected. The Civil War resulted from two very different views as to what the United States was. The federalist view was that the United States was ruled by a strong federal government and the weak state governments being subordinate. The origionalist view was that the United States was an association of sovereign states with a weak federal government handling those things the states couldn’t handle themselves.
Remember that the Civil War was _not_ about slavery from the Union perspective. And even for the Confederacy — slavery was nothing more than the proverbial ‘straw that broke the camel’s back’ that ignited the war.
So your racism comment is nothing more than an example of the left taking advantage of an ignorance of history being used to manipulate you.