After his departure the animals take over the business of the farm and everything is pretty much hunky dorey until Jones returns with some men from town. The animals are expecting this and repel the invaders. Increasingly however, the pigs assume more and more control over the other animals until in the end the rest of the farm can no longer tell the difference between the pigs and humans with which they had sought independence from in the first place. There are many stories like Animal Farm that could be effectively used to teach history. Ideally, I think that students would be better served if Literature and history were taught in the same class.
Literature allows a much deeper understanding of historical events.
Almost every character and memorable prop or setting was symbolic.