What makes a source primary?
Primary sources are original documents and objects which were created at the time. Typical examples include letters, diaries, photos, newspaper articles, eyewitness accounts, autobiographies, government reports, paintings, maps, etc. In actuality, it can be more complicated and can depend on the topic/time period.
Always clarify with your professor.
Useful Tips for finding printed primary sources in library catalogs
Browse footnotes and bibliographies of books, encyclopedias, and articles for information about primary sources.
Search the Library Catalog for primary sources--both unpublished manuscripts and modern editions in print and online, sometimes in translation, of original primary sources. Use the "advanced search" with the terms for primary sources below as subjects, not keywords.
Sources means primary sources in a library catalog and it is the most powerful term in the list. It can mean a printed, edited, modern edition of an archival source; or it can mean a collection of excerpted, translated sources which might have the words "reader" or "documents" in the title; or it can mean a book about primary and secondary sources. All are invaluable. The footnotes and bibliography of any of them will lead to more sources.
Biodiversity Heritage Library
Primary Sources in English Translation: Antiquity
Primary Sources in English: Medieval
Bibliography of English translations from medieval sources (Olin Library Graduate Study Center, Room 501 and Olin Reference Z6517 .F24) Outdated and superseded, but can still be useful on occasion, especially for brief works (a single letter or poem) or excerpts of longer works contained within books or articles.