Where does this phrase come from ?

And why is it so important?

Thank you

Well, am posting some useful bits from wikipedia on the same: http://en.wikipedia.org/wiki/Ivy_league

"The Ivy League athletic conference, founded in 1954, consists of eight private institutions of higher education located in the eastern United States. The term, with its connotations of academic excellence, selectivity in admissions, and a certain amount of academic elitism, dates back to at least 1935...

All of the Ivy League institutions share some general characteristics: They are among the most prestigious and selective schools in the U.S., they consistently place close to the top of college and university rankings; they rank within the top one percent of the world's academic institutions in terms of financial endowment; they attract top-tier students and faculty; and they have relatively small undergraduate populations, ranging between 4,078 for Dartmouth College and 13,700 for Cornell University and modestly sized graduate student populations, ranging between 1,666 for Dartmouth and 14,692 for Columbia. Seven of the eight schools (Cornell University being the exception) were founded during America's colonial period. Ivy League institutions, therefore, account for seven of the nine colleges chartered before the American Revolution. The Ivies also are all located in the Northeast region of the United States. "

These schools include: Brown, Columbia, Harvard, Yale, Dartmouth, Cornell, Upenn and Princeton.

Hope this helps...