Why are the pigs immediately accepted as leaders in Animal Farm?

In chapter two, the pigs announce that they have taught
themselves to read and write:

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The pigs now reveal that during the past three
months they had taught themselves to read and write from an old spelling book which had
belonged to Mr. Jones's children and which had been thrown on the rubbish
heap.

The other animals are
impressed with the pigs' education. Not only have the pigs taught themselves to read and
write, but they have created the principles of Animalism. The other animals like the
sound of Animalism. This is one reason the other animals accept the pigs as leaders. The
pigs' philosophy sounds good. It makes the other animals feel there is hope. The other
animals want to see change and the pigs are now offering hope. The pigs have named the
farm Animal Farm, and the other animals like the sound of Animal
Farm.

Also, Snowball is quite the leader and is later
honored with a medal for bravery:

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Snowball shows his expert use of military
strategy during the attack—which becomes known as the Battle of the Cowshed—and is later
awarded a medal.

No doubt,
the other animals recognize the great leader that Snowball is. He is organized in his
efforts. The other animals accept his expertise and consider his ideas
effective.

Also, it was Old Major, a pig, who initially
planted the desire to rebel against Mr. Jones and his animal
cruelty:

The
animals gather in the barn as Old Major, the prize boar, tells them that he has thought
about the brutal lives that the farm animals lead under human bondage and is convinced
that a rebellion must come soon, in which the animals throw off the tyranny of their
human oppressors and come to live in perfect freedom and
equality.

The animals
respected Old Major and trusted him. It makes sense that the pigs would take up
leadership where Old Major left off. After all, everything Old Major talked about made
sense to the animals, or at least most of the animals. What animal would not desire
perfect freedom?

Most importantly, the pigs have created a
commandment that all animals are equal. This is important to the other animals and they
accept the pigs as their leaders for they talk a good talk.