Starting in Chapter 1 and going to Chapter 6:
The animals gather in the barn to discuss revolution and Old Major teaches them the song "Beasts of England".
Old Major dies.
The animals rebel and succeed.
Snowball and Napoleon create the seven commandments of animals.
Snowball shortens the commandments to one: "four legs good, two legs bad".
Battle of Cowshed occurs when the neighboring farmers try to retake the farm. The animals win.
Snowball is chased off the farm when he tries to push through his windmill idea.
Squealer convinces the other animals that Snowball was a criminal.
Napoleon announces the building of the windmill, presenting it as his own idea.
The animals workload continues to increase over the course of the next year.