Animal Farm actually spans from the 1917 Revolution until the end of WWII. If I remember correctly, the attack on the farm by the ousted farmer and colleagues was for example meant to symbolise the invasion of the Soviet Union by Nazi Germany. The 'Lenin' pig also dies quite early on, and the whole book is more or less a criticism of Stalinism.
Anyhow, Animal Farm's a really good read. Orwell managed to write a book that's as easy to read as a children's book, but still recognisably references many of the flaws with the development of communism in the Soviet Union. And he sort of predicted the eventual outcome of the Stalinist/Soviet-style communist system.
I also agree with the 1984 recommendation, it's a great book. I actually like it even more than Animal Farm.
You can say what you want about the Trump administration, but at least it's bringing back the golden age of dystopian novels.