This paper seeks to explain the astonishing proliferation of diversity-related offices (DROs) in U.S. higher education over the past 50 years. We collected original archival data on the DRO adoption years for a nationally representative sample of 235 U.S. colleges and universities. Using event history models, we tested alternative theories for the organizational determinants of DRO adoptions from 1968 through 2020. We find that universities’ internal characteristics were influential earlier on (1968-1994), while the external organizational environment mattered more in the (...) later period (1995-2020). Selective universities are earlier DRO adopters throughout the analysis period, suggesting that the institutionalization of diversity in U.S. higher education has been, at least to some extent, a “follow-the-leader” process. We conclude by reflecting on the relationship between the persistent valorization of diversity in U.S. higher education, growing contestations, and current efforts to revitalize a more race-conscious and equity-focused agenda on American campuses. (shrink)