Someone help me out with literary critisism

Okay, so I've got a big nasty lit assignment fast approaching, and I'm having a little trouble figuring out what the difference between New Historisism and Cultural Materialism is. I know that one is British and one is American, but beyond that I can't seem to tell. So if anyone here knows, please help me out.

Eeek

It's been a long time since first year English, so this may not be entirely correct. I also don't have my notes here, so this is all based off of memory.

New Historicism is more about looking at a piece of literature from the context of the time it was written in. Studying a piece of literature this way, you look at the works that were available to the author at the time that may have influenced him or her, as well as social, political, and economic situations that may have impacted the writer and/or his or her writings.

Cultural Materialism is more about studying popular or well-read pieces of literature and studying why they are considered still important to the cultures that read them today. I think the idea was to see why these particular 'important' works remained popular, and the thought process was it must be to instill certain values in the general culture of society.

So, for example, from a New Historicism perspective of Shakespeare, you'd look at what sort of things were happening in society, and what economic or political situations may have influenced his writing. Coming at Shakespeare from the Cultural Materialist perspective, you'd look at what parts of his works make him still relevant today, and what themes, values and messages are emphasized that people may still find ideal.

Again, I may have gotten mixed up somewhere, since this is from memory from a class I took like two years ago. I say if all else fails, wikipedia is always here.