Wow, he musta said something real controversial, like "history was a real thing that actually happened, it's not something you can change by editing textbooks or wikipedia. I was there, here's how it went". Magas really hate it when people do that.
One of his earliest childhood memories, he later said, was watching a 17-year-old black boy being lynched after being "accused of impregnating a white girl."....ah, that and civil rights issues that they didn't want 7th graders to read about.
Makes sense. I have not read this book and I don't believe there's any itemized list of reasons you can look up for why different books were banned (that would defeat the purpose, which is that people don't talk or think about them). I was just guessing based on the title, because it mentions his "journey through the 20th century", that he talks about one or more parts of history that the magas like to whitewash. It sounds like you found it.
Yeah. I deleted my original comment to you asking why they banned it. Then I looked it up in wiki and revised my reply. There are no good reasons for banning and book burning.