As (what I consider to be) an interesting story, I saw a very good program on confederate monuments in the South on TV the other day. It was pointed out that the vast majority of confederate dead were buried in mass graves on the various battlefields during the war. No markers, no names, no nothing.
After the war, there were tens of thousands of widows and mothers and children who had no grave to visit for their lost fathers, sons and brothers. These confederate monuments became the only substitute for hundreds of thousands of individual graves which did not exist.
This, and not glorification of slavery, was the principle reason for so many monuments.

They were dead men with no grave. Almost none of whom ever owned a slave.