This is far different from the Holocaust. These monuments aren't glorifying slavery and how we should round up all the blacks, they're dedicated to the men who fought who in the state regiments during the war. Most (over 90%) of Southern troops didn't own slaves and came from poor, rural families who were essentially subsistence farmers. Plus, they were treated just as poorly by wealthy plantation owners as groups like the Irish in Northern cities.

Think of it this way: we have the Washington monument, right? Washington broke his nation's laws at the time by rebelling against Britain, and he was a southerner who owned slaves. Does the Washington monument commemorate him as a slave owner, or as a man who fought for the US and helped gain us our independence? Lincoln fought against and killed many of the Indians in the Black Hawk War. Seattle has a statue of Lenin. Lenin was responsible for one of the bloodiest wars in Russian history, the overthrow of a democratic government (Kerensky's, not the Tsar's), and the starvation/murder of millions of people. Does that statue commemorate him as a murder, or as a leader of the workers?

It's almost as if history is nuanced and not cut and paste. Museums certainly tell history as well, but I fail to see just why we can't have both museums and these statues do so as well.