When asked about the bans, Salinger once said, “Some of my best friends are children. In fact, all my best friends are children. It’s almost unbearable for me to realize that my book will be kept on a shelf out of their reach.”
The book introduced slang expressions like the term screw up (as in, “Boy, it really screws up my sex life something awful”). Literary critics have both hailed and assailed the novel, which broke the mold with its focus on character development rather than plot. Holden Caulfield, the novel’s protagonist, has since become a symbol of adolescent angst. In 1980, 25-year-old Mark David Chapman shot Beatles legend John Lennon in front of his Manhattan home and later gave the book to police as an explanation for why he had done it.
Source: https://entertainment.time.com/2011/01/06/removing-the-n-word-from-huck-finn-top-10-censored-books/slide/the-catcher-in-the-rye-2/