Top Feeder Rankings (From Publication)
Per the site College Transitions, they have a page on "Top Feeder Rankings (adjusted for undergraduate enrollment)."
I would argue that the adjustment is necessary, as 50 kids from a 1,000 person liberal arts college going to Harvard is much more impressive than 50 kids from a 40,000 person public university. The ranking seems to line up with a former WSJ "Top Feeder Schools" ranking. No surprise to see the same old suspects (Ivy League, NESCAC, etc.). I think the average person might be surprised that small LACs lead to great outcomes as well.
2 University of Chicago
3 Claremont McKenna College
5 Williams College
10 Amherst College
14 Wellesley College
The list goes on to 30 or so schools. Vandy, Tufts, Columbia, Wesleyan, W&L, Colby, Bates all make it later.