What are primary sources? Primary sources enable the researcher to get as close as possible to what actually happened during an historical event or time period. Primary sources can be treaties, photographs, legislation, diaries, speeches, interviews, letters, manuscripts, newspaper articles, artifacts, or other materials. Depending on your field of study, a primary source might also be an original scientific experiment or anthropological fieldwork.
Primary sources are not books or journal articles that provide secondary analysis, or describe something that happened somewhere else.
Primary sources can be in any format. Primary sources might be original documents in archives, republished in a contemporary book, available online, or preserved on microfilm. The content of the material -- rather than the format -- determines whether or not it's a primary source.
Finding primary sources is sometimes easier if you can identify a specific name or event to search with. Secondary sources like the Encyclopedia of Chicago can be used to identify people, places, and events.