User blog comment:Zathronas/Analysis by an author: Organization The Faunus & The White Fang/@comment-10380701-20131229013019/@comment-10380701-20131230011214

The war that created the White Fang is likely the Faunus War Revolution. It fits well with what Oobleck was talking about in episode 11. I think it works like this, unless there's suppose to be another war between the Faunus Rights Revolution and the present day that we haven't heard of... (Mind you, this is just pure speculation on how the war worked)

With the decisive battle at Fort Castle, the war was tipped into the Faunus' favor and the humans were forced to make a truce with them, thus ending the war. Regardless the Faunus were still considered lower than humans so the White Fang was created as a peaceful protest for their rights.

Fast forward five years and we have the new White Fang.