But context matters. Being a "natzi" today is commonly known as wrong and not acceptable bc we have a pretty solid history to back that up.
However owning slaves in Colonial times was as common as owning a car today with no precedent to show otherwise. We have the luxury of looking at the past and critiquing it, but when you are living in the current time and it was socially acceptable, I dont completely blame them for it. I can separate the contributions to our country and the nuances of his everyday life. I'm not saying slavery was ok or acceptable, but it was acceptable back then for their own reasons.
Similar example would be Bill Cosby. His comedy was great, but unbeknownst to everyone, he was drugging and raping women. At no time in his life, was that an acceptable action. So even though it came out years after his career ended, I have no problem never watching anything he did ever again.
In 100 years, it may be socially decided that betting money and profiting off of men playing a barbaric game for our entertainment, which turned out to be detrimentally bad for their health and caused high rates of premature disablement and suicides, was evil and outlawed. Should any contribution you or I possibly do in our lifetimes be removed b/c we participated in that entertainment?
But that said, there are currently societies and cultures that still engage in slavery and other barbaric acts. Yet we have "Canceled" our historic figures with more hatred and vitriol than we direct at those current groups.