A boar named Old Major had a strange dream one night about how when he was a young pig, his mother would sing a song but she only knew the first three words along with the tune. In Old Major's dream, he knew all the words and found out that the name of the song was "Beasts of England" so he taught it to the rest of the farm animals.
After Old Major finished explaining his dream and telling on about how the animals are treated so unfairly, he warned them all that he was going to die soon and a rebellion needs to happen in order for the animals to get what they deserve/ treated better. The next day Old Major died and the animals decided to rebel Mr. Jones.
The animals then break into where their food was stored after starving because nobody fed them. Mr. Jones had got home late and fell asleep while other farm staff didn't bother feeding them so they broke in creating a catastrophic scene.
Mr. Jones was awaken by the sound of the animals breaking into all the food. He marched towards the barn to see what shenanigans were in action not knowing that he was going to be taking place in the Battle of the Cowshed. All the animals had a plan set up to kill Mr. Jones so they would no longer have to obey his rules. Their set up had unfortunately not gone to plan and Mr. Jones ended up shooting; and shortly after, killing Snowball. Later on, Mr. Jones gives up on the animals and leaves to go to a house for alcoholics and then dies.
After Mr. Jones dies, the animals regret trying to harm him and regret making him so mad to the point where he left. The animals did not enjoy the responsibility of doing hard labor for themselves without the advantage of having hands or other human limbs.
After Mr. Jones dies, all the animals discover the different "occupations" they are meant for on the farm to make it easier for them to achieve the needs of the farm. Later on in story the pigs develop characteristics like walking on two legs such as a human and they couldn't tell the difference.