This publication is intended for teachers bringing a class to visit the National Archives in Washington, D.C., for a workshop on primary documents. The National Archives serves as the repository for all federal records of enduring value. Primary sources are vital teaching tools because they actively engage the student's imagination so that he or she may visualize past events and make sense of their reality and meaning. This publication describes two primary documents found at the National Archives: the cotton gin patent and a "map of the United States Agreeable to the Treaty of Peace of 1783." Photographs of both documents are included as are exercises for students. (DB)