This research explores the new tradition of creating mass murder memorials in the United States at the turn of the twenty-first century. Using written and oral history sources in combination with memorial designs, I explore the planning processes undertaken by five different communities: Virginia Tech, Columbine, University of Texas, Oklahoma City and Edmond, OK. I analyze what these case studies reveal about how changing cultural expectations and political needs transformed commemorative practices concerning violence in the late twentieth and early twenty-first centuries. By exposing how the timely interventions of national figures increasingly shaped local commemorative aspirations, my research illuminates how the brief period of national unity in the immediate aftermath has been discursively and materially foregrounded as the heart of national public memory narratives of mass murder. I argue that at the turn of the twenty-first century the memory of victims of mass murders"assuming something akin to the role that fallen soldiers have played for the bulk of American history"are now viewed by a range of political, religious and cultural actors as a highly effective means of bolstering perceptions of local, organizational and national unity. This project contributes to the interdisciplinary literature on commemoration in three ways. First, I challenge the literature on memorials built in the immediate aftermath of violence and tragedy by illustrating how these memory sites are increasingly but the first stage of the material culture of public memory. Second, my theory of a ritualized assemblage develops the existing literature by forwarding a concept well suited to analyze the relationship of between seemingly disparate memory sites. Lastly, the rhetoric of what I call the Myth of the Slaughtered Citizen contributes to the literature on nationalism and commemoration by explaining how the victims of mass murder were culturally substituted into the commemorative role traditionally held by fallen soldiers to promote a sense of local and national unity. / Ph. D.