William Henry Jackson was an American photographer and painter, born on April 4, 1843. He is best known for his stunning photographs of the American West, particularly his work documenting the landscapes of Yellowstone National Park. His images played a significant role in promoting the park and the idea of conservation in the late 19th century. In addition to photography, Jackson was also an accomplished artist and explorer. He worked as a surveyor for the United States Geological Survey and contributed to the mapping of the western territories. His legacy continues to influence the fields of photography and environmental preservation.