The dramatic transformation of Latin American capitals in the mid-twentieth century by housing projects for the middle and working classes is one of the most familiar and important parts of the region’s architectural history. Whether in Caracas, according to the designs of Carlos Raúl Villanueva; in Mexico City, under the direction of Mario Pani; or in Rio de Janeiro, with the guidance of Affonso Reidy, modern housing projects reshaped the daily lives of countless people and functioned as symbols and instruments of urban growth and government-led modernization schemes. Ana María León’s Modernity for the Masses is about how the immigrant Catalan architect Antonio Bonet might have contributed to such change in the Argentinian capital yet didn’t.León’s study focuses on three unbuilt housing schemes that Bonet designed between 1943 and 1957, and argues that the projects demonstrate the ways the architect’s admiration for the ideals of Spanish surrealism and Francophone modernist city planning principles competed and intersected in his work. Over the course of her account, the projects—each for a different site in Buenos Aires—grow in size, scale, and complexity, from Casa Amarilla (1943), to Bajo Belgrano (1949), to Barrio Sur (1955–57). At the core of her argument is the claim that, despite their differences, the projects represented sophisticated efforts on the part of their governmental patrons to control an ever-expanding urban population, which she calls “the masses,” following the prevailing social and political theoretical conceptualizations of the term in Argentina when Bonet was there. These “masses” were comprised, in the case of the first two projects, chiefly of working-class citizens, many of whom were Indigenous Argentinians, descendants of Italian or Spanish settler colonists, or a combination of these, who moved to the capital from the countryside. (Barrio Sur’s audience was middle class.) These people, the author argues, were imagined by architects and patrons as alternately threatening or malleable for political aims, but in any case, as “other.” León is interested in the prospective complicity of Bonet’s schemes in shaping the behavior of the masses using principles rooted in the urban planning theories of the Congrès Internationaux d'Architecture Moderne (CIAM), and his appeals to emotion with roots in psychoanalytic theory and the revolutionary aspirations of Spanish surrealism. Bonet designed projects for three very different regimes—a dictatorship advised by conservative intellectuals, the populist but anticommunist government of Juan Perón, and the military dictatorship that ousted him. León tracks the ways the architect adapted designs and representational strategies to suit the ambitions of these administrations and the prevailing political mood.In its positioning of buildings and projects at the intersection of politics and international developments in the arts, Modernity and the Masses joins a growing and impressive list of books that similiarly frame modern architecture in Latin America. Like Luis E. Carranza, Luis M. Castañeda, and George F. Flaherty, León understands architecture as intimately related to developments across a wide field, including literature, photography, and film, and she devotes close attention to the modes and meanings of its representation. Her book also belongs to the burgeoning scholarship on Latin American art that emphasizes the centrality of international exchange and immigration, which includes outstanding monographs by Jennifer Josten, Harper Montgomery, and Fabiola López-Durán. Bonet’s intimate connections to the European avant-garde—he was a student of Josep Lluís Sert, worked in Le Corbusier’s atelier, and knew Picasso, Miró, and Dalí—frame León’s thorough discussions of Bonet’s collaborations with Roberto Matta, Jorge Ferrari, and Juan Kurchan. They also set the stage for her discussion of Bajo Belgrano in relation to the centrality of psychoanalytic theory, nostalgia, and the photography of Grete Stern. León locates developments in the visual arts in an Argentinian intellectual milieu informed by the writings of José Ortega y Gassett, French surrealist Roger Caillois (both of whom contributed to theories of the “masses”), Jorge Luis Borges, and the elite circle of writers and artists centered on Victoria Ocampo.León weaves her account of the intellectual climate of Buenos Aires through three main chapters on the housing projects. These are preceded by one on what is perhaps Bonet’s best-known built work in Argentina, the Artists’ Ateliers at Suipacha Street (1938–39). León’s explication of this splendid building sets the scene for her sometimes rather far-ranging but deeply researched analyses later in the book. One of the strengths of the text is its discussion of the urban history and form of modern Buenos Aires. León’s interpretations of the highly charged relationships between solids and voids, buildings, plazas, boulevards, monuments, and neighborhoods add plenty of interest to a city that at many points reads as conservative and derivative (if monumental, and impressive as an exercise in planning and political will). Another contribution is the sharp focus on the implicit construction of the architectural subject—in the case of the othered “masses”—by architects and their patrons during the critical, and underexamined, decade of the 1940s.León notes of her own writing that “Bonet himself often recedes into the background” (11). Indeed, her chief interests are positioning his projects within a variety of international and national discourses—including those on monumentality, planning, social control, and the revolutionary potentials of modern architecture—and in arguing for architecture’s complicity in perpetuating the aims of authoritarian regimes, of which she regards Bonet’s work as emblematic. The architect’s ultimate turn toward a technocratic rationalism that served the aims of capitalism and dictatorship at the end of his time in Argentina and after his return to Spain, was anticipated, she argues, in his “complicated fascination with, and ultimately fear of, the latent irrational power that masses were understood to possess” (4).At points, particularly in the introduction, the discussion of politics feels heavy-handed, even overreaching. Certainly, it is the case that politicians in Argentina (and probably most countries) have used building projects and representations of them in support of unethical aims. Yet it seems a stretch to say that Bonet’s projects “embody the architect’s own unconscious thoughts and desires in regard to these populations [the masses]” (4). She concludes that the preponderance of spaces for consumption over those that support “congregation” (such as plazas) today “reveal the neoliberal state as the logical conclusion of the dictatorships that oppressed the [South American] continent in the second half of the twentieth century” (15). León understands the masses in relationship to contemporary theorizations of the concept but, unlike some scholars, leaves intact without much comment the potentially vague concept of the state. Modern architecture appears to mean the forms and ideas associated with Le Corbusier and CIAM; this is fine given Bonet’s direct connection to them, but defining the term specifically and contextually seems paramount to the broad project of shaping a diverse and expansive historiography of twentieth-century architecture, of which León is a part.Although this is not its intention, with varying degrees of depth Modernity for the Masses situates Bonet’s housing projects in relation to broad issues in architectural modernism in the Americas—the relationship between urban and rural; the role of cosmopolitan experts in rapidly changing societies and growing cities; the imagined and real relationships architects in the Americas had with European avant-gardes; the constructions of race, class, and history in the service of national and hemispheric politics. León says that Bonet’s work in Argentina constitutes “minor history” and is a lesson in failures. Her work, nevertheless, is a major contribution to the history of modern architecture in the Americas.