Primary sources are materials that were created during the historical event they describe or were recorded soon after by people with firsthand knowledge of the event. Some primary sources, such as the Declaration of Independence of the United States of America, are so important that they become, or are the cause of, important historical events. Other primary documents, like census records, take the form of large series of statistical data. Photographs and older films can also be primary documents. See Interpreting Illustrations.

How to read a primary source:

• Take note of who the author of the source is and what that person's role was in the events described.
• Record any specific facts the source contains.
• The exact words (or images) of a primary source may be important so read carefully.
• If asked by your instructor, be prepared to compare the primary source materials to secondary sources that refer to it. Did the author of the secondary source accurately summarize the contents of the primary source?