Jump to: Preparation Procedure Evaluation In this lesson, students use Library of Congress primary sources to recognize the impact photographer William Henry Jackson and artist Thomas Moran had on the creation of Yellowstone National Park. As members of the 1871 Hayden Expedition, Jackson's and Moran's images helped to shape Americans' ideas of the West. Students compare the photographic images with the paintings that resulted. They explore the legislative records and historical mapping of the a