My story was not about Michael's or Troy's shame but about my son's shame -- and tears and his sleepless nights. Michael quit wanting to play with my son that day. He didn't enter junior high for another year and a half, Their were no other black children in his class, he began playing with another white boy in our neighborhood.My family story was intended to illustrate how deeply my children felt their classmate's pain and how they got a front row seat to the terrible enduring legacy of slavery. I'd be surprised if it turned out the fairly young teacher ever ran that project again. Troy's shame was not because of the color of his skin but because it was yet another example of the powerlessness of his enslaved ancestors.. Truly, the shame belonged elsewhere, and by my son's account of the incident, shame was sorely felt by all in the classroom that day.
Michael may have distanced himself from your son for reasons having nothing to do with that incident. When children hit junior high they often gravitate to new friendships. Michael may have desired friends who looked like him and deeply understood his challenges of being dark skinned in a country where Whites continue/d to hold most of the power.
My son learned all about the holocaust a few years later and because he has German ancestors he took that very hard also.
Of course we have to learn history but the general attitude from teachers these days is the same as yours. Tell what happened and make sure the white kids feel the full force of guilt about what white people did in the past -- and yes it is about skin color. Never mind that the child's actual ancestors might have been in Ireland during the slave years or Greman-Americans in America during WWII -- it's the simple fact of being white that makes them in the wrong to most people.
It's clear from this very forum that hatred and bigotry toward Christians is perfectly acceptable, statements about how "nasty" they Christians are and how everyone of them turns rotten the minute they leave the church, are are allowed to stand when such statements would be attacked if they were made about any other religion or race. It's tied in with what is being taught in schools from elementary through college that white people are bad people, period.