How can I reword or connect the two parts of this sentence?
The truth behind the controversy is more than the remembrance of soldiers during the American Civil War, but the enslavement to Caucasian slave owners and the many African American slaves whose lives were taken away at an instant because of their skin color.
I'm not sure what is required here. If I was to rewrite this convoluted sentence, I would make it two sentences. "...Civil War. The controversy involves the memory of the enslavement..."
The problem with it as written is that it is unclear what the memory of slaves has to do with monuments to (I assume) Confederate soldiers. That needs to be made clear, one way or another.