Whenever I read about another effort to protect the young from historical nastiness (the latest being the new edition of Mark Twain's The Adventures of Tom Sawyer and Huckleberry Finn with "the pejorative racial labels" removed), I think of Roald Dahl's Pig a very creepy story for adults. In it a child is raised in isolation as a vegetarian and has an epiphany as an adult when first encountering meat. Wanting to know more about this wonderful new food he goes to a slaughter house and.... well, go find and read the story if you want to know what happens. Suffice it to say it is a cautionary tale about keeping hard realities from children.
The Twain flap also makes me think of Susan Campbell Bartoletti's They Called Themselves the K.K.K., a book for children that is full of those "pejorative racial labels" in the oral histories, interviews, and other primary sources that Bartoletti employs with extraordinary heft and power.
History ain't pretty, but that doesn't mean it shouldn't be known.
Also at educating alice.