[People inside and outside stopped train alongside a canyon in Mexico]

William Henry Jackson (1843-1942) was an American painter, photographer, and explorer who is best known for his pioneering work in documenting the American West. He was born in Keeseville, New York, and after serving in the Union Army during the American Civil War, he became interested in photography. Jackson worked as a photographer for the United States Geological Survey, and he was a member of several expeditions to the West, including the Hayden Geological Survey of 1871. During these expeditions, he produced a large number of photographs that helped to document the landscape and the Native American cultures of the region. Jackson's photographs were instrumental in promoting the idea of creating national parks in the United States. He was also one of the founding members of the Detroit Photographic Company, which produced a large number of postcards and other commercial products based on his photographs.