Confederate statues are not “history” but rather efforts to give a giant middle finger to civil rights progress. The article below makes that point clear, explaining the timing, location, and motivations of the people who put up those statues. In a nutshell, those statues were put up by white supremacists in response to civil rights progress that they didn’t like.
Beyond that, the confederates are losers who took up arms against their country, and slaughtered good American soldiers to try and perpetuate slavery. People like that are unworthy of glorification by statues.
As a further example, consider the case of Iowa. Iowa was in the Union during the civil war. Many soldiers from Iowa gave their lives to put a stop to the the confederacy. Confederate terrorists entered at the border with Missouri and raided Iowa, killing Iowa farmers. Yet in the year 2007, a confederate monument was erected in Iowa. That is entirely about promoting white supremacy. It isn’t “history” to glorify those murderous traitors.
Taking down statues that glorify evil people is not “erasing history.” You don’t see statues honoring Hitler, yet we certainly haven’t erased the terrible atrocities committed by the Nazis from history. Instead, we teach about evils of the Nazi party, and have museums dedicated to ensuring no one forgets. The same approach should be applied to the confederates.
A good article that explains the situation in much more detail: https://www.npr.org/2017/08/20/544266880/confederate-statues-were-built-to-further-a-white-supremacist-future