Timothy O'Sullivan was a photographer who worked with the US government as it explored the Old West in the 1860s and 70s. This collection of his work shows compositional excellence as well as surprising technical competence from his unwieldy box camera. O'Sullivan used the collodion wet plate process, meaning that each shot would have had to have been prepared, taken, and developed out in the field with a portable darkroom. Think about that the next time you upload a picture of your cat with Facebook Camera.