Can newly ascendant social movements revitalize the militant culture of older, institutionalized movements? Recent studies have focused on relations between new ascendant social movements like the civil rights, women's, and peace movements that emerged during the postwar cycle of protest, and therefore have been unable to address this question. Focusing on revitalization as a qualitatively different form of intermovement relation, the authors examine the possibility that civil rights movement insurgencies and organizations revitalized workplace labor militancy during the postwar decades. Time-series models show that the civil rights movement fueled an expanded militant worker culture that challenged management and sometimes union leadership. However, this revitalization of labor militancy was contingent on institutional context (stronger in the public sector than the private sector) and form of insurgent action (protests, riots, organizations) differentially embedded in historical phases (civil rights versus Black Power) of movement development. Theoretical implications for the study of social movements, industrial relations, and class conflict are discussed.