The Forbidden Library reports that 1984, was challenged in Jackson County, Fla. (1981) because the novel is "pro-communist and contained explicit sexual matter."
E-notes explains of Animal Farm,
Completed in 1944, the book remained unpublished for more than a year because British publishing firms declined to offend the country's Soviet allies. Finally the small leftist firm of Secker & Warburg printed it, and the short novel became a critical and popular triumph. It has been translated into many languages but was banned by Soviet authorities throughout the Soviet-controlled regions of the world because of its political content.
Orwell originally prepared a preface which complains about British government suppression of his book, self-imposed British self-censorship and how the British people were suppressing criticism of the USSR, their World War II ally. "The sinister fact about literary censorship in England is that it is largely voluntary. ... [Things are] kept right out of the British press, not because the Government intervened but because of a general tacit agreement that ‘it wouldn’t do’ to mention that particular fact." Somewhat ironically, the preface itself was censored and is not published with most copies of the book.