<p>This series of Ngrams compares the number of bound book mentions of The Little Three (Amherst, Williams and Wesleyan) + Swarthmore during the period coinciding with the introduction of women undergraduates to the student populations of the formerly all-male colleges:
[Google</a> Ngram Viewer](<a href=“http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Swarthmore+College&year_start=1965&year_end=2008&corpus=0&smoothing=3]Google”>http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Swarthmore+College&year_start=1965&year_end=2008&corpus=0&smoothing=3)</p>
<p>Notice the precipitous tumble that all three formerly all-male colleges take compared to Swarthmore just about ~1975, followed by an extended length of time during which all four seem to wrestle for the title of “best co-ed LAC”. Swarthmore, of course, had a headstart on that title from its founding in 1864.</p>
<p>Notice the very similar results when Oberlin is substituted for Swat:
[Google</a> Ngram Viewer](<a href=“http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Oberlin+College&year_start=1965&year_end=2008&corpus=0&smoothing=3]Google”>http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Oberlin+College&year_start=1965&year_end=2008&corpus=0&smoothing=3)</p>
<p>To a limited extent with Pomona, before petering out:
[Google</a> Ngram Viewer](<a href=“http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Pomona+College&year_start=1965&year_end=2008&corpus=0&smoothing=3]Google”>http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Pomona+College&year_start=1965&year_end=2008&corpus=0&smoothing=3)</p>
<p>But, to no extent at all with Middlebury:
[Google</a> Ngram Viewer](<a href=“http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Middlebury+College&year_start=1965&year_end=2008&corpus=0&smoothing=3]Google”>http://ngrams.googlelabs.com/graph?content=the+Wesleyan+University%2Cthe+Amherst+College%2Cthe+Williams+College%2Cthe+Middlebury+College&year_start=1965&year_end=2008&corpus=0&smoothing=3)</p>
<p>Not sure how to explain the results with Middlebury, except that perhaps to some extent the playing field was leveled in favor of he Little Three to the degree that prior to 1975, if you wanted to go to a New England college that was both small and co-ed, Middlebury and Colby were pretty much all that were available. After 1975, the monopoly was broken.</p>