This essay explores how certain residents of Baltimore, Maryland, in the late 1960s perceived governmental efforts to construct an urban highway system as an enclosure of the commons. Baltimore's political and business leaders believed that highways were required to keep the city, and particularly downtown businesses, economically competitive. Highway plans targeted African American and, to a lesser extent, working-class white neighborhoods. Because it destroyed community resources, limited housing options, and caused general degradation in surrounding neighborhoods, residents saw the construction of the highway as a form of enclosure. This is an inversion of the traditional definition of enclosure; the road was for public use, whereas much of the property condemned and destroyed was privately owned. But antihighway activists argued that the road would only benefit a privileged few, primarily white suburbanites, while destroying resources publicly available to minority and working-class communities. Understanding Baltimore's highway protests as anti-enclosure activism shows how the residents of postwar cities in the United States experienced destructive urban renewal and highway construction projects. It also portends recent efforts by municipal governments to condemn and reappropriate urban land for private development, while simultaneously claiming that these actions are for the public good.