In the study of history as an academic discipline, a primary source (also called original source or evidence) is an artifact, a document, diary, manuscript, autobiography, a recording, or any other source of information that was created at the time under study (from Wikipedia) -- and may include newspaper reports at the time of events, historical and legal documents, eyewitness accounts, results of experiments, statistical data, audio and video recordings, speeches, and art objects.

Online databases provided millions, if not billions, of pages of digitized primary source materials. 

The Special Collections Department in the Main Library provides an extensive list of primary source material: http://www.lib.uiowa.edu/sc/resources/researchresources/