The 1967 Universal and International Exhibition, the Montreal world's fair commonly known as Expo 67, produced both continuations of and crises in the emancipatory project of modern architecture. Like many world's fairs before it, Expo 67 was designed to mediate relations between peoples and things through its architecture. The origins of this work lay in the efforts of Daniel van Ginkel and Blanche Lemco van Ginkel, architects and town planners who, in remarkable reports, drawings, and architectural ideals advanced between 1962 and 1963, outlined the basis of a fundamentally new, though never fully realised, world's fair in the late twentieth century. Party to the Congrès Internationaux d'Architecture Moderne and its influential prewar edicts on functionalist town planning as well as to groups like Team 10 and their opposition to diagrammatic generalisations by an emphasis on the personal, the particular, and the precise, the van Ginkels also drew on contemporary theories and practices of North American urban renewal when first conceiving Expo 67 as an instrument for redeveloping downtown Montreal. The resulting work, Man and the City, which officially secured the world's fair bid but remained unbuilt, carefully drew on the legacies of most great exhibitions, especially those of the nineteenth century, in order to conceive of sufficiently heroic structures making immanent novel forms of human interaction, social control, and the technical organisation of space. In 1967, this was to suggest a new world historical project - in a space existing for only six months but crowded with 50 million visitors - promoting senses of fraternal self-awareness through the unrelenting promise of progress. The resulting well-known Expo 67 theme, Man and His World, was a paean to contemporary humanism first used by the van Ginkels and their architect allies to reject the most enduring symbols of world exhibitions: the nation-state and its emblematic architecture. They imagined new kinds of architecture that could somehow engender new senses of political consciousness (inspired by, for example, UNESCO or the celebrated Family of Man photography exhibition of 1955) outside nationalist chauvinism. This was a vision of late modernity: a transitional form of political subjectivity still clinging to the shared passions of the citizen (thus for the polis) before being subsumed by mass culture - in other words, a moment during which nationalisms could still be channelled into alternative forms of political belonging free of narrow self-interest. The belief marked every aspect of the van Ginkels early plans and had half-lives in two consequential works: the theme pavilions Man the Producer and Habitat 67, which, with outward emphasis on the aesthetics and technics of innovative structures (and mass production), were seen as fulfilling the ambitions of the megastructural movement in the 1960s. As such, theses architectures of late modernity reflected a markedly modernist conviction of long duration: on the one hand, an abiding faith in technological salvation and, on the other hand, the sense of some liberative social mass giving rise to a new citizen of the world. At the very same moment, this universalism was fraught with ambiguity: on the one hand, any abiding faith in techno-scientific salvation was shaken in the aftermath of global war and the terror of nuclear holocaust; on the other hand, assumed geopolitical ideals were being upended, however temporarily, by, say, decolonisation and resulting alternative global alignments on a postwar world's fair). Expo 67, perhaps the most consequential twentieth-century world's fair in terms of utopian hopes of modern architecture, was prey to these and related desires to reinvigorate the modern project of uniting instrumental reason, mass edification, and popular spectacle in a genuinely new public realm. It would irrevocably shape the ways in which Canada, as a host nation purposely celebrating its centennial in the ambit of a world's fair, was to confront its collective sense of cultural representation and global belonging.