This article examines the contested and unprecedented process by which the Baltimore & Ohio Railroad laid tracks through Baltimore’s city streets in the 1830s. Laying tracks in busy thoroughfares raised profound questions about the meaning of urban space and the economic function of the city. Track opponents held that city streets should remain open to free-flowing traffic and condemned railcars for monopolizing public space. Track advocates countered that urban prosperity was rooted in the rapid, efficient movement of goods. This was not a battle of traditionalists versus progressives but a clash between competing visions of urban modernity. Examining these competing urbanisms gives us a window into the spatial dynamics of capitalism and the ways in which industrialization reconfigured local space.