The Ivy League is no doubt the most prestigious league academically, but not athletically. Interestingly, it was not formally organized until 1952.
See also the "Black Ivy League".
This conference has been known by several different names:
The current members of the conference, and the years of their joining:
Schools that were members at one time:
Organized 1895 as the "Intercollegiate conference of Faculty Representatives", also known as the "Western Conference" and later, the "Big Ten Conference". For many years, the most prestigious league, at least in football; most schools rank high academically as well.
Original member that withdrew:
Originally, the Missouri Valley Intercollegiate Athletic Association: MVIAA (1907-64)
The conference was known as the "Big 6" (1928-47),
and then the "Big 7" (1947-57)
Big 8 (informally from 1957; officially, 1964-94)
Big 12 (1994- )