Imagine the twentieth century without photography and film. Its history would be absent of images that defined historical moments and generations. Today such a history feels insubstantial and imprecise, even unscientific. And yet photographic technology was not always a necessary precondition for the accurate documentation of history. The documentary impulse that emerged in the late nineteenth century combined the power of science and industry with a particularly utopian (and often imperialistic) belief in the capacity of photography and film to capture the world visually, order it, and render it useful for future generations. This book is about the material and social life of photographs and films made in the scientific quest to document the world. It explores their creation and production as well as the collecting practices of librarians, archivists, and corporations. Together, the chapters of Documenting the World call into question the canonical qualities of the authored, the singular, and the valuable image, and transgress the divides separating the still photograph and the moving image, as well as the analogue and the digital. They also definitively overturn the traditional role of photographs and films in historical studies as passive illustrations.