I want to become a lawyer in America, how do I do this?

I am currently at a grammar school in Manchester, so I want to go and become a lawyer in the US as opposed to a barrister in the UK, not that I don't like Britain, I have just always wanted to live in America, so what kind of schooling do I have to do after A-Level's to do this, I would have asked on careers day in school but I was off ill on that particular day, so any help would be much appreciated :)