There is a substantial and growing body of research -- many hundreds of papers -- that has identified several pedagogical approaches that are significantly more effective than traditional lecturing, even for large classes in conventional auditoriums. And yet traditional lecturing still dominates in most subjects at most institutions. This talk describes a program launched six years ago at Cornell University, by its College of Arts and Sciences, to address this contradiction. In the program's first iteration, large introductory course sequences in physics and biology were transformed by their respective departments. In two subsequent iterations, the program grew to include 16 departments, affecting more than 140 faculty and thousands of students annually. The Active Learning Initiative, as it is called, expanded to include the entire university in 2019, and now has projects in the sciences, social sciences, engineering, and the humanities. This talk will discuss what was done, why and how it was done, and some of the impressive outcomes that followed from the changes. The talk will also discuss institutional challenges and opportunities created by such projects, from the perspective of the (then) dean.