Violence can shape political behavior across generations, but the social mechanisms underlying this process are only partially understood. We propose that collective memories permit the inter-generational transfer of attitudes induced by violence, even when state recognition is weak, making them prone to mobilization following changes in the political environment. We study a case of indiscriminate violence against Italian civilians by French North African soldiers during World War II. Using a geo-targeted survey experiment, we document that memories of violence are locally transmitted within the family and community and causally affect attitudes toward immigration. Using electoral outcomes and party platforms from 1948 to 2018, we then show that increasing the nationalist content of a party’s manifesto results in more gains in formerly victimized communities. This paper sheds new light on the social nature of memory, and how it allows conflict experiences that are marginalized from national narratives to be politically consequential.