This dissertation examines how institutions and individuals navigate the histories of racial difference and settler colonialism by focusing on architectural preservationists' explanations of what are referred to as white cities. Through dialogue between architectural history, international relations, and critical heritage studies, I map the making and remaking of the histories of white cities, or what were designed as "European" zones – in opposition to "Indigenous" zones – that brought together modernist architecture, white supremacy, early twentieth-century European settler colonialism, and architectural preservation. My focus on preservationists' narrations of these white cities extends interdisciplinary work charting their historical production from a group of scholars focusing on the relationship of architecture in the production of domination in European colonialism. My work extends this scholarship by shifting to preservationists' narrations of white cities through the question: how do preservationists remake the histories of racial difference and settler colonialism that underpinned the production of white cities? In this dissertation, I argue that preservationists remake the histories of racial difference and settler colonialism that produced white cities by relying on what I refer to as didactic narratives to legitimate preservation interventions. Preservationists use these didactic narratives to reframe white cities as part of national histories, the universalism of the World Heritage List, and the history of the modernist movement in architecture and planning. My argument advances by showing preservationists' appropriations of the didactic narratives in the World Heritage List inscription materials for White City of Tel Aviv (2003), Rabat, Modern Capital and Historic City: A Shared Heritage (2012), and Asmara: A Modernist African City (2017) and through ethnographic fieldwork with local preservationists in Casablanca and Tel Aviv. To frame these analyses, I map the institutional changes within the UNESCO World Heritage Committee that sought greater legitimacy by expanding the typological and geographical scope of the World Heritage List. To do so, the institution enlisted the International Committee for the Documentation and Conservation of Buildings, Sites, and Neighborhoods of the Modern Movement (DOCOMOMO-International) to recraft the criteria to include twentieth-century modernist architecture onto the List. However, DOCOMOMO promoted a particular way of interpreting white cities through the didactic narratives that led to the proliferation of white cities on the World Heritage List. By charting the different ways that preservationists appropriate the didactic narratives in the World Heritage List materials and in the text of semi-structured interviews and from participant observation, I show how the intersecting power structures of white supremacy and settler colonialism that were embedded in the production of white cities are adapted by preservationists in the co-constitution of international institutions, disciplinary knowledge, and individual subject positions. / Doctor of Philosophy / This dissertation considers how the histories of race and colonialism are narrated by architectural preservationists. I do so by focusing on preservationists' narrations of white cities, "European" enclaves designed in opposition to "Indigenous" zones in early 20th century settler colonialism. By focusing on the preservation of what were designed as racialized spaces, I explore how these histories of racial difference and colonialism are mediated by forms of knowledge, institutions, and individuals. Yet it is the focus on preservationists that I detail how preservationists silence, downplay, or mobilize the histories of white cities through three different narrative tropes of national histories, the universalism of the World Heritage List, and modernist movement architecture and design. I show how these narrative tropes justify preservation interventions while making some histories more accessible and others less so. To analyze how preservationists remake the histories of white cities, I map the creation and transformations of the primary international preservation organization, the World Heritage List. These institutional changes led to the addition of white cities in Asmara, Rabat, and Tel Aviv based on preservationists' adaptations of the three narrative tropes. I then show how these same narrative tropes are appropriated by local preservationists to remake the histories of race and colonialism in white cities. By drawing attention to the ways that the histories of race and colonialism are remade through the intersections of individuals, institutions, and forms of knowledge, the project shows how knowledge on the modernist movement is implicated in the constitution of power in the World Heritage List and in consolidating privileged subject positions. Moreover, my analysis opens up questions on the co-constitution of institutions, forms of knowledge, and individual subject positions. Lastly, the analysis demonstrates that individuals have the potential to challenge – rather than to uphold – the constellations of power etched into white cities. I show one instance of architectural preservationists challenging these structures of power in the preservation effort of Les Abattoirs in Casablanca in 2009-2013.