I've been reading NELL IRVIN PAINTER's book "The History of White People" which is Copyright 2010 and published by W.W. Norton and Company. I'll be sprinking this blog with excerpts from that book here and there.
This is the story of European slavery ("Whites enslaving Whites"), class in Europe and America, which included indentured servants and slaves, and the notions of who was more worthy.
There was a progression of early theorists who decided that being low class had everything to do with intelligence and character as genetic; the "imbeciles" and "morons" and "the unfit" were the target of sterilization for the good of society. ( I note: This is the danger of genealogy motivated by snobbery!)
Painter does an excellent job of reporting the notions of race or ethnicity as individuals are considered to be of more or less worthy because of these notions. Racism was inherent in the descriptions of Europeans as "Nordic" or "Alpine" or "Mediterranean" as determined by physical features rather than country of origin.
This book may remind you of your own bad experiences or what your ancestors experienced because of their origins.
Perhaps they were considered of subnormal intelligence and not up to decent jobs because they were Italian or Slovak?
Are you yourself still experiencing intolerance and prejudice based, not on your character or deeds, but because of your ethnicity?