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CEE/EGR 102: Engineering in the Modern World: Primary sources -- technology in context

Guide to library resources, print and electronic, to explore social and political issues raised by engineering innovations.

Primary v Secondary Sources

The Standard Definition

In historical writing, a primary source is a document or physical object which was written or created during the time under study. These sources were present during an experience or time period and offer an inside view of a particular event. Some types of primary sources include:

* ORIGINAL DOCUMENTS (excerpts or translations acceptable): Diaries, speeches, manuscripts, letters, interviews, news film footage, autobiographies, official records
* CREATIVE WORKS: Poetry, drama, novels, music, art
* RELICS OR ARTIFACTS: Pottery, furniture, clothing, buildings

Examples of primary sources include:

* Diary of Anne Frank - Experiences of a Jewish family during WWII
* The Constitution of Canada - Canadian History
* A journal article reporting NEW research or findings
* Weavings and pottery - Native American history
* Plato's Republic - Women in Ancient Greece

What is a secondary source?
A secondary source interprets and analyzes primary sources. These sources are one or more steps removed from the event. Secondary sources may have pictures, quotes or graphics of primary sources in them. Some types of seconday sources include:

* PUBLICATIONS: Textbooks, magazine articles, histories, criticisms, commentaries, encyclopedias

Examples of secondary sources include:

* A journal/magazine article which interprets or reviews previous findings
* A history textbook
* A book about the effects of WWI

Another Possible Usage

PRIMARY SOURCE (more frequently PRIMARY TEXT) is sometimes used in a different sense in some types of classes. In a literature class, for example, the primary source might be a novel about which you are writing, and secondary sources those sources also writing about that novel (i.e., literary criticism). However, if you were writing about the literary criticism itself and making an argument about literary theory and the practice of literary criticism, some would use the term PRIMARY SOURCE to refer to the criticism about which you are writing, and secondary sources other sources also making theoretical arguments about the practice of literary criticism. In this second sense of primary source, whatever you are primarily writing ABOUT becomes the primary source, and secondary sources are those sources also writing about that source. Often this will be called the PRIMARY TEXT, but some people do use primary source with this meaning.


Tertiary Sources

Just so you can keep up with all the scholarly jargon about sources, a tertiary source is a source that builds upon secondary sources to provide information. The most common example is an encyclopedia. Consider a particular revolution as an historical event. All the documents from the time become primary sources. All the historians writing later produce secondary sources. Then someone reads those secondary sources and summarizes them in an encyclopedia article, which becomes a tertiary source. If someone then collected a bibliography of encyclopedia articles on the topic, that might be a quarternary source, but at that point the whole thing just becomes silly.

U. S. Patent Sites (free)

A patent is a property right granted by the Government of the United States of America to an inventor “to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States” for a limited time in exchange for public disclosure of the invention when the patent is granted.

Patents are historically significant primary documents covering over two centuries of U.S. innovation.

Historical statistics

Looking for data to back up your argument?

  • Historical statistics of the United States: earliest times to the present. Editors in chief, Susan B. Carter ... [et al.]. New York: Cambridge University Press, c2006. Pliny Fisk Library (SXF) HA202 .H57 2006 The essential starting point for U.S. historical statistics. Covers population, work and welfare, economic structure and performance, economic sectors, and governance and international relations. The introductory essays discuss the data sources and broad trends and are very valuable.
  • International historical statistics. the Americas 1750-2005. Brian Mitchell. 6th ed. Basingstoke: Palgrave Macmillan, 2007. Social Science Reference Center (SSRC) HA175 .M55 2007
  • International historical statistics. Europe, 1750-2005. B.R. Mitchell. 6th ed. Basingstoke, Hampshire; New York, N.Y.: Palgrave Macmillan, 2007. Social Science Reference Center (SSRC) HA1107 .M5 2007
  • International historical statistics: Africa, Asia & Oceania, 1750-2005. B.R. Mitchell. 5th ed. Basingstoke, Hampshire; New York: Palgrave Macmillan, 2007. Social Science Reference Center (SSRC) HA4675 .M552 2007 These three volumes are the first place to look for international historical statistics. The are similarly arranged and cover: population and vital statistics, labour force, agriculture, industry, external trade, transport and communication, finance, prices, education, and national accounts.

Need more?

Digitized Historic Materials


AccuNet/AP Multimedia Archive Contains the current year's photo report from the Associated Press & a selection of more than 700,000 images from their negative & print library dating from the 1840s.

Image Quest Over two million images of objects, events, places, works of art, sports, and scientific pursuits, from dozens of collections such as Getty Images and the National Geographic Society.

Library of Congress: Prints & Photographs Online Catalog Searchable catalog; many of the images have been digitized.

American History in Video Newsreels from the 20th century, plus television and movie documentaries on American history.

And don't forget advertising as a source of images -- check newspapers, magazines and the two online collections below: 

Ad*Access (Historical Advertising Collections at Duke University)
Images for over 7,000 advertisements printed in U.S. and Canadian newspapers and magazines between 1911 and 1955.

Includes posters, broadsides, pamphlets and printed advertisements illustrating everyday life in 18th, 19th and early 20th century Britain.
Digital Princeton University Library Collection of high resolution digital images of selected materials from the library's collections.

*A Note about citing images. Images must be cited like all other resources. If you use an image you did not create, you must provide a citation. Images should be cited in all cases, even if the image is very small, or in the public domain. The citation should be accessible in the context of the image's use (within a Powerpoint presentation, on a web page, in a paper, etc.). Image citations should include the following information at a minimum:

  • Title
  • Creator name
  • Repository information (museum, library, or other owning institution)
  • Image source (database, website, book, postcard, vendor, etc.)
  • Date accessed

It is also useful to include date and rights information, if known.

Citations can be formatted according to the citation style you are using.