What event sparks the animal revolution in animal farm?

The animal revolution in "Animal Farm" is sparked by the charismatic speech of Old Major, an elderly boar, who inspires the animals to rebel against their human owner, Mr. Jones. He shares his vision of a society where animals are free and equal, free from human exploitation. Following Old Major's death, the animals, fueled by his ideas, rise up against Mr. Jones after enduring neglect and hunger, successfully driving him off the farm. This rebellion marks the beginning of their quest for self-governance and equality.