
Timothy H. O’Sullivan originally began his career in photography by working for the military to document the Civil War (1861-65). He later began photographing landscapes on military and geographic expeditions, during which he used a wet-plate collodion process, a technique which allowed him to have a portable darkroom that could develop images within about 15 minutes. This photograph was shot during his participation in the 1871 expedition in the west led by First Lieutenant George Wheeler. Despite the harsh conditions of his journey, O’Sullivan was still able to capture the rich beauty of the Black Canyon in Colorado; its rough edges and monumental height contrasting the smooth, glass-like surface of the river.