What explains the rise of race-conscious affirmative action policies in undergraduate admissions? The dominant theory posits that adoption of such policies was precipitated by urban and campus unrest in the North during the late 1960s. Based on primary research in a sample of 17 selective schools, we find limited support for the dominant theory. Affirmative action arose in two distinct waves during the 1960s. A first wave was launched in the early 1960s by northern college administrators inspired by nonviolent civil rights protests in the South. A second wave of affirmative action emerged in the late 1960s, primarily as a response to campus-based student protests. Most late-adopting schools were those most favored by the Protestant upper class. Our findings are most consistent with a theoretical perspective on institutional change in which social movements' effects are mediated by the moral and ideological beliefs of key administrators.Why, how, and through what mechanisms were race-conscious affirmative action programs originally instituted in college admissions? The dominant theory, which comes from the sociological literature on institutional change in higher education, attributes the rise of race-conscious affirmative action to two specific types of social disruption during the late 1960s. According to this view, campus protests and urban riots in the North posed a powerful new threat to the symbolic legitimacy of the social order. College administrators resolved the problem by incorporating racial considerations into the admissions process. Under this theory, race-conscious affirmative action was prompted by social upheavals in the late 1960s that precipitated a cultural shift in the permissibility of race-sensitive policies. This theory is widely influential, but the empirical evidence to substantiate it is limited.Our article contributes to the literature by analyzing the origins of race-conscious affirmative action in a nonrandom purposive sample of 17 highly selective undergraduate institutions. Drawing on new