Ivy League Group Agreement to all intercollegiate sports, effective with the 1955–56 basketball season. This is generally reckoned as the formal formation of the Ivy League. As part of the transition, Brown, the only Ivy that hadn't joined the EIBL, did so for the 1954–55 season. A year later, the Ivy League absorbed the EIBL. The Ivy League claims the EIBL's history as its own. Through the EIBL, it is the oldest basketball conference in Division I. As late as the 1960s many of the Ivy League universities' undergraduate programs remained open only to men, with Cornell the only one to have
Ivy League to refer to the Ancient Eight plus several other schools for purposes of alumni associations, university affiliations, or endowment comparisons. In his book "Untangling the Ivy League", Zawel writes, "The inclusion of non–Ivy League schools under this term is commonplace for some schools and extremely rare for others. Among these other schools, Massachusetts Institute of Technology and Stanford University are almost always included. The University of Chicago and Duke University are often included as well." In their 2015 book "Acing Admissions", Mehta and Dixit write, "The ["Ivy Plus" schools] include, but are not limited to: Massachusetts Institute of Technology (MIT),