History teaches no lessons at all if it allows people to believe that it was somehow the most natural thing in the world for people to be racist in the US in 1897 or at any other time or in any other part of the world.
What is perhaps the most disheartening thing is that that is still the only question that people see. Is the film racist or is it not racist. Do we look at a fil of Annie Oakley sharp-shooting and ask if it is anti-woman? Do we look at a film of Eugen Sandow rippling his muscles and ask if it homophobic?
What we are watching here is a show star performing just as we are when we watch Annie Oakley or Eugen Sandow. The boy in the film is quite clearly a seasoned vaudeville performer doing his stuff. The racecourse and the table and the jockeys are all just mise en scène. So the first question we might ask ourselves is whether he's a good dancer and if we enjoy his performance or not. Personally I think he does a great job and one sees the genesis of modern dance forms - he could be twisting - far more clearer in some of the more staccato buck and break dancing that generated much more ephemeral fashions for crude, slightly violent dances of the "apache" variety.
The audience looks mixed to me - not just "white" - a bit difficult to tell with people in the US because they are nearly all obviously mixed race to some degree or another - and I see no mockery here. I just see a cute little dancer doing his stuff. Their music and dance has been an enormously vector of emancipation for black people in the US and for all I, or anyone else, knws, this boy would go on to be a veritable king of the strut. It certainly cannot have done him any harm to have had his moment in front of the camera.