This dissertation presents the first architectural history of American hackerspaces, a project designed to explore and understand the evolution of a countercultural form of architecture and entrepreneurial social space that has become common in postindustrial and post-recession US cities. Examining six hackerspaces of varied sizes and constituencies established in the Detroit and San Francisco metropolitan areas between 2007 and 2013, the dissertation considers how hackerspaces interface with American public life and public space. It argues that while nonprofit hackerspaces position themselves as public resources to ameliorate post-recession economic and social precarity, spatially and socially they tend to repeat the exclusionary politics of public space that permeate US urban and architectural history, where spaces that strive to be all-inclusive alternatives to state and market structures fracture along identity lines and unevenly allocate their resources. The dissertation examines, for example, how predominantly white and masculine cultures in the first US hackerspaces led to communal reckonings, increasing insularity, and offshoot hacker spaces that center women, LGBTQIA communities, and other marginalized constituents. Using fieldwork and engagement with vernacular architecture, global urbanism, and media studies literature, the dissertation explores the tension-filled transition of hacker communities from diffuse countercultural scenes to formal participants in the urban fabric. Using interdisciplinary methods to interpret original photographs, architectural documentation, and ethnographic data collected between 2018 and 2022, the dissertation demonstrates how hackerspace communities active in the San Francisco and Detroit areas inscribe digital and political utopianism in physical space. Hackerspace cultures and buildings thus offer microcosms of how aspirations of openness, diversity, and access to public resources outside the bounds of corporate culture, academia, and government programs fracture along identity lines. Centering the fugitive spatial practices of hackerspaces, the dissertation offers new directions for an inclusive architectural history of normalized precarity in post-recession and COVID pandemic-era cities in the US.