Imagine the twentieth century without photography and film. Its history would be absent of images that define historical moments and generations: the death camps of Auschwitz, the assassination of John F. Kennedy, the Apollo lunar landing. It would be a history, in other words, of just artists' renderings and the spoken and written word. To inhabitants of the twenty-first century, deeply immersed in visual culture, such a history seems insubstantial, imprecise, and even, perhaps, unscientific.

Documenting the World is about the material and social life of photographs and...