Nope, you also don’t see these people trying to stop slavery around the world today. Over 150 countries allow slavery today and only outraged by slavery 170 years ago.
A famous line in the movie, The Man Who Shot Liberty Valance, was "When the legend becomes fact, print the legend." In the case of widespread perception of the eras of slavery and Jim Crow, this is a problem where the "legend" is too widely believed and used to undermine this country and its traditional values.