This dissertation examines how nonfiction film was used to observe, analyze, and understand the built environment in the United States between 1896 and 1920. By focusing on the seriality of film and contemporary visual media, it shows how the introduction of the new medium altered the configuration of knowledge and practice related to architecture, building, and city planning during the first two decades after its inception. In discussing “serial architectures,” this dissertation defines four modes of seriality through which we can view film in relation to the built environment: narrative, temporal, archival, and geographical seriality. Each chapter describes one type of seriality and illustrates a point of intersection with architecture and urbanism at the turn of the century. Through the examination of nonfiction films including street scenes by Edison Manufacturing Company and American Mutoscope and Biograph Company, construction films by those producers and educational filmmakers including the Ford Motor Company, motion studies conducted by industrial management researchers Frank and Lillian Gilbreth, and industrial and educational films depicting geography, this dissertation investigates media as an instrument for understanding the built environment. While some films are analyzed in close detail, considering seriality at the level of narrative and structural composition, seriality is also discussed across media in series, approaching groups of films, photographs, and prints as objects of study. In demonstrating how motion pictures served as a means for the observation, collection, analysis, and representation of spatial and temporal information through their serial properties, this dissertation elucidates how motion pictures served as a tool for the development and demonstration of architectural and urban concepts at the turn of the twentieth century. By revisiting narratives of architecture and urbanism in the United States through the lens of media history, it contributes to debates on media and architecture, as well as the agents involved in the development of modern design, building, and city planning.