That is a good question CCMint. I figured if they were issued during the war by confederate states you could bunch Southern States and CSA notes together. I think the CSA notes were more of a middle finger to the USA, while Southern State notes were more about daily commerce plus it drove home the idea of states rights and not depending on a centralized treasury. I'm sure CSA notes would help in interstate commerce - no doubt. I'm just guessing at all this mind you.
Oh I just got two more in the mail from Heritage this weekend. I can't wait to get home to post my rebel notes!
Here are my Confederate notes. Hope you enjoy them: The first two are the same denomination and both T66 varieties. I just happen to have two of them.