In partnership with the National Archives at Philadelphia, we’re pleased to announce a new guide for teachers and students, “Comparing Primary and Secondary Sources,” which is newly published on the website for National History Day Philadelphia. Created to help students with their research for National History Day projects, the guide was prepared by Melissa Callahan, an experienced social studies teacher who is the education outreach coordinator for The Encyclopedia of Greater Philadelphia and a graduate student in history at Rutgers-Camden. This work was supported by a grant from the National Endowment for the Humanities to the Mid-Atlantic Regional Center for the Humanities (MARCH), which produces The Encyclopedia of Greater Philadelphia.