The Library's Guide to Primary Sources provides a sampling of resources that may prove helpful in historical research. Look, too, for collections of documents published as anthologies or for important historical texts from the many sources listed. If you have questions, just ask a librarian!
Photo credit: Retrieved from the Library of Congress, https://www.loc.gov/item/91482188/
The term "primary source" is defined differently by various disciplines. In the humanities, a primary source is a historical document, such as a diary, memoir, a work of art, a news account published when an event was fresh - something from the historical period under examination. In the sciences, a primary source is a scientist's write-up of their research that includes their methods and results, as opposed to science journalism or a summary of research (a "review article") that has been conducted to provide an overview of research on a given topic.
A secondary source is one that has already been analyzed by someone else. Moving even further from the unfiltered event is a tertiary source such as a textbook or encyclopedia, that summarizes knowledge in general terms.
Using primary sources, whether in science or the humanities, helps a researcher get as close as possible to the subject under examination. Using primary sources can be a good way to point your reader to the raw materials of your ideas and provide an opportunity for you to do your own, original analysis.
For more about primary sources, check out our guide to primary sources available in our library.