Unofficially:
Chi Omega 1936
Zeta Tau Alpha 1940
Phi Mu 1962
Alpha Delta Pi 1966-1988
Delta Gamma 1969
Kappa Delta 1971
Delta Delta Delta 1972
Kappa Kappa Gamma 1977-1984
Alpha Gamma Delta 1989-?
Alpha Chi Omega (closed but I don't know the dates)

I'll verify your KKG dates. That's what's on our website.

A little late on this thread...its interesting how people are pointing out the "in-state" dynamics of MSU. I am a MSU Phi Mu alum from Tennessee and went into rush basically clueless! I did have recs for all the chapters except Tri-delta. I am a Phi Mu legacy as well. During rush, I never felt overlooked for being out of state, but once on the chapter side and then on Panhellenic, I do recognize that Mississippi does tend to cluster its small-town girls into certain chapters...(eg: Many Tupelo girls go AAA, many Meridian girls go XYZ, a lot of delta girls go BBB...) but even over the course of a few years that can change. Out of state girls going through rush just need to have some stand-outs on their application and SEND A PICTURE with a recommendation to each chapter to help the chapters remember who they are during the week...it doesn't hurt to make it a good picture with a memorable feature (fun top, cute background, pets, etc)! I love the MSU greek system...message me with any questions!

That's a heartbreaking thread to read.