Ive been wondering what started the infighting between Houses Slytherin and Gryffindor...What do u think?

Slytherin wanted to keep all the Hogwarts students pureblood. He didn't trust Muggleborns to keep the magic and the location a secret from their families. The other founders, especially Griffindor, disagreed about this.

Well, the answer is simple. Slytherin wanted all the students of Hogwarts to be Pure-Blood. That was just predajust (Can't spell). Gryffindor dissagreed with Slytherin's attitude. They argued for a while, then SLytherin eventually left. That's the story for today, Peeps!