Things that seems to get clearer to me the more I hear people argue about this are:

Phi Beta Kappa was the first greek letter organization. but it's an honor society! Not like a fraternity in the sense we think of it. (like brothers living in a house, with a ritual etc. etc.) That's why Kappa Alpha is the first Social Fraternity. And since their fouding all but two US presidents have been alumni of greek organizations.
and most fraternities were formed either by masons or children of masons who wanted to be part of something special like their fathers.


I'm also very interested in other secret collegiate societies, like skull and bones etc etc. if anyone can list stuff on that I'd appreciate it.



PS that link was very informative (and my fraternity was on there, oh yeah, )