This dissertation resituates key social and political debates of American modernity within the discourses of the nonhuman that dominated turn-of-the-century intellectual life—evolution and the technologies of industrial capital. I argue that prominent writers like Jack London, Charlotte Perkins Gilman, Mark Twain, and Frank Norris sought to investigate and discursively shape the newly modern nation by first settling the proper human relationship to our nonhuman others, both organic and technological. The result is an experimental naturalism that uses a wide range of evolutionary hypotheses as starting premises for fiction that intervenes in the period’s contentious debates surrounding gender and sex, race and ethnicity, class and labor, empire and global corporate capital. While helping launch American modernity, its ‘experiments’ also issue in national and global futures that run counter to the period’s dominant narratives and the ones that seem, from our vantage point today, inevitable., Experimental naturalism, as I develop it here, also brings to light a crisis in human exceptionalism in America around 1900 that emerged in response to the particular confluence of evolution and industrial capitalism. My authors struggle to locate the ‘exceptional’ human in a technoscientific modernity that newly blurred the taxonomical distinctions between humans, organisms, and machines. In so doing, they generate a biopolitical discourse concerned with industrial capital’s administration of all life as a site of value and utility. Experimental naturalism alternately develops, shores up, and challenges the biopolitical techniques of modern technoscientific capitalism—techniques like Taylorism, eugenics, scientific agriculture, domestic and sanitary science, and the efficiency movement. I argue, then, that experimental naturalism builds towards an American politics of life that implicates human and nonhuman alike. The modern organism, as it emerges from out of this literature, vacillates between the poles of resource and wilderness, technoscientific production and the unregulated fecundity of biological reproduction., Each of the four chapters that make up this dissertation zooms in on one particularly significant and contentious way that American life was reassembled around 1900. The first half of the dissertation follows naturalist interventions into the nation’s domestic modernity, focusing on urbanization and “The Woman Question.” The second part turns to America’s place in the world, and in particular issues of imperialism, immigration, and transnational corporate finance. My argument throughout remains methodologically committed to a view of nature and culture as mutually constitutive realms: Each chapter considers how the nonhuman effect on culture rebounds back on organic life, thus helping to ‘modernize’ American nature. , My first chapter tracks Jack London’s attempt to envision American modernity outside of the industrial city’s biopolitical imperatives, which threaten to unravel the anthropocentric evolutionary order. I argue that London, in his late Sonoma fiction, works out a socialist theory of modernity centered on the suburbs. In this regard, he builds on the work of early urban sociologists, who saw, in America’s suburban trend, a resolution to the social woes that plagued the machine age. Ultimately, I find that London’s pastoral reorientation of modern American space only affirms the totalizing grip of machine processes, wherever they are located. London’s dystopian fiction, in turn, renders industrial capital itself a minor term in a larger evolutionary story governed by the microbe, a creature immune to biopower. I argue throughout this chapter that London’s vision of city and country issues in part from his lifelong commitment to Ernst Haeckel’s “materialistic monism,” which functioned for the author as both an evolutionary and a biopolitical discourse., In Chapter Two, I turn to Charlotte Perkins Gilman’s effort to articulate a modern woman that would properly fulfill nature’s mandate for the female organism. I find that Gilman relied on turn-of-the-century efficiency discourse to manage the specter of female-animal fecundity raised by her own evolutionary feminism. Ultimately, the author’s resolution of “The Woman Question” would have American women enacting their biological destiny largely through the biopolitical regulation of all unruly organisms. Gilman’s writings thus offer a unique vantage point for examining the influence of early feminist theory in shaping a twentieth-century technocratic politics of nature. This chapter stands apart from the rest by proposing a broad disciplinary intervention into nonhuman studies: I argue here that Gilman’s depictions of animality as fungal suggest the value of building an ‘organism studies’ perspective into the nonhuman turn, and animal studies, in particular., Chapter Three focuses on Mark Twain’s famous anti-imperialist politics, which, I argue, find their basis in Twain’s evolutionist commitment to biological determinism and his critique of human species exceptionalism. In Part I of this chapter, I read Twain’s Connecticut Yankee in King Arthur’s Court as a prescient critique of America’s budding technocratic imperialism. Here, Twain imagines the subjects of American empire as ‘trained’ into natural bodies, as nature was conceived in the machine age—standing ready to be deployed as resource for American profit. Part II examines Twain’s interest in the microbe as an organic model for an American nation that would ‘globalize’ internally through immigration, rather than externally through imperial adventure. I suggest that 3,000 Years Among the Microbes poses a naturalist alternative to The Connecticut Yankee’s ‘exceptionalist’ model of imperial selfhood: This is a form of interconnected selfhood firmly embedded in both nature and culture. The ecosystemic world of ‘I’s’ that we find in 3,000 Years is a democratic one, requiring a plethora of competing perspectives for its existence., Finally, Chapter Four traces the metaphorical logic of Frank Norris’s wheat commodity in The Octopus as pointing to an infinitely expansive American frontier-nation centered on the Chinese market. In Norris’s ‘wheat theory of politics,’ the American social organism ends up completely disappearing into a global commercial utopia that soon turns nightmare. Politics is effaced by commerce, signaling, in a sense, the coming of a universal biopolitical order organized not by sovereign territories, but by the flow of capital. This chapter turns to Hannah Arendt’s proto-biopolitics of “society” and “the social” to flesh out the contours of such a world. But I also engage Norris’s writings in the context of an earlier moment in biopolitical theory: Friedrich Ratzel’s Lebensraum geopolitics, which Frederick Jackson Turner picked up in formulating his famous Frontier Thesis. In concluding this chapter, I transfer the wheat from the politics of the “Open Door” to that of “Yellow Peril.” This last reading of Norris points to not only the death of the American organism, but also the end of ‘technocratic evolution’ in America.