Argh, please help me figure this out! Need to write a statement of jurisdiction for US District Court (more)?

It is based on diversity of citizenship and amount in question, so it definitely goes to the District Court. I'm thinking this would be in Federal Rules of Civil Procedure, but I can't find it on Westlaw and my professor is sometimes not really good about returning emails quickly. Can anyone please tell me where I can find the code/statute/whatever that would be appropriate for m jurisdictional statement? It's for my capstone project and I'm just absolutely stuck on this part (I'm actually pretty smart, lol, but this one detail is killing me!)

Thanks for any help you can give!