The Greek system at Cornell,   which I define as the  mainstream national  social fraternities and sororities on the Ithaca campus,  had fully matured by the start of the 1940's with roughly 60 fraternities and 13 sororities.   Many chapters were 70+ years old by that point and the character of the campus and the surrounding streets of Ithaca had been stable for decades.

WWII would cause a major disruption to the system,  as would explosive  postwar growth,  the counterculture of the 60's and early 70's,  and finally the changing demographics of the school going into the 21st century.

The history of Cornell's sorority system is pretty easy to summarize.  The 13 sororities of the 1940's continue to dominate with a club of ten still in existence.  The Sigma Kappa,  Chi Omega,  and Alpha Omicron Pi  chapters have gone away;  some more than once.   A number of other major national sororities have come and gone for short periods.  Of these outside organizations only Alpha Chi Omega has successfully established itself on campus.  

Dormant national sorority chapters

• ΑΟΠ - Alpha Omicron Pi, 1908–1962, 1989–2008 

• ΔΖ - Delta Zeta, 1908–1932 

• ΧΩ - Chi Omega, 1917–1963, 1987–2003 

• ΣΚ - Sigma Kappa, 1921–1956 

• ΦΣΣ - Phi Sigma Sigma, Beta Xi chapter, 1954–1969, 2011–2023 

• ΔΦΕ - Delta Phi Epsilon, 1960–1988, 1994–2003 

• ΑΓΔ - Alpha Gamma Delta, 1985–1996 

• ΦΜ - Phi Mu, 2014–2021 

I did a lot of research when I was back in Ithaca teaching a CAU class in 2007.  I took all this back to Alabama and put it away.  There was no obvious useful application - it was just research for the fun of solving a historical mystery.  18 years later I finally returned to CAU (2025) and I took my 2007 material with me.  By that point I had done a few historical websites and realized that this had potential as a fun topic for that type of website.  And this time I found a lot more material about the topic on the internet including a lot of Cornell Sun articles about fraternity misbehavior and general foolishness.