Digital Public Library of America (DPLA) Primary Source Sets are designed to help students develop critical thinking skills by exploring topics in history, literature, and culture through primary sources. Drawing online materials from libraries, archives, and museums across the United States, the sets use letters, photographs, posters, oral histories, video clips, sheet music, and more. Each set includes a topic overview, ten to fifteen primary sources, links to related resources, and a teaching guide. These sets were created and reviewed by the teachers on the DPLA's Education Advisory Committee. To learn more about this project, visit DPLA.