Where, when, and in what geographic contexts were women able to enter the film exhibition business as it grew from a technological novelty into a major industry and fixture of the modern American landscape? Mapping Movies prompts these new questions and more, exploring cinema’s emergent social and spatial environments by developing a Geographic Information System (GIS) using the Environmental Response Management Application (ERMA) pioneered by the National Oceanic and Atmospheric Administration and the University of New Hampshire. ERMA is a data management platform that aggregates diverse datasets and information streams, including those from crowdsourcing, into a fast, user-friendly online map. By adapting ERMA for cinema history, the result is a GIS prototype that charts the spread of movies in New Hampshire, locates women’s missing footprint in film exhibition, and visualizes deep forces shaping an emerging medium in an era of urbanization, modernization and suffrage.