Secondary Sources: What Are They?

National History Day, an annual program for elementary and secondary students designed to "teach essential historical literacy that motivates students to secure the future of democracy," defines secondary sources as follows:

What are secondary sources? Secondary sources are works of synthesis and interpretation based upon primary sources and the work of other authors. They may take a variety of forms. The authors of secondary sources develop their interpretations and narratives of events based on primary sources, that is, documents and other evidence created by participants or eyewitnesses. Frequently, they also take advantage of the work of other historians by using other secondary sources. For example, the author of the history textbook which you use in school probably did not use too many primary sources. Instead, textbook authors usually rely on secondary sources written by other historians. Given the wide range of topics covered by a typical textbook, textbook authors could not possibly find and use all the relevant primary sources themselves.

Here are some examples of secondary sources.

REFERENCE BOOKS: Reference books are good starting points for basic information about your topic, but they are only that. They should not be included in your bibliography. Look for general information in: encyclopedias, special historical dictionaries, and historical atlases. General encyclopedias such as World Book can provide you with basic information, while subject encyclopedias such as the Encyclopedia of the North American Colonies provide a bit more detailed information. Encyclopedia articles often have bibliographies which can direct you to some of the major secondary sources for a topic.

Biographical dictionaries are compilations of biographies of people selected because of their fame, accomplishments, membership in a particular group, or some other distinguishing characteristic. Each person's entry is a succinct summary of his or her life, often written by an expert.

Atlases are compilations of maps. Maps created at the time of an event—such as battlefield maps created at the time of a battle—are primary sources, but maps created later, such as those tracing the migrations of Indian tribes, are secondary sources.

POPULAR PERIODICAL LITERATURE: Popular magazines, indexed in the Readers' Guide to Periodical Literature, can give you ideas for and some general information about particular topics. Many magazines and newspapers publish articles dealing with individuals or historical issues. For example, in the mid-1990s many U.S. newspapers and magazines wrote about Nelson Mandela, whose political activism helped revolutionize South African society by ending apartheid, and who became president of South Africa in 1994 after spending 28 years in prison for his politics. Starting a project on apartheid, you might begin here, and get ideas for interesting topics about the events that led to this revolution.

HISTORY TEXTBOOKS: Yes, really! Your textbook can be a great place to get ideas for topics and find out about the general context of your topic. If you're interested in the invention of the telescope as it revolutionized astronomy, first do some background reading on the scientific revolution as a whole, perhaps in a general textbook on European history. This will help you understand how your topic fits in with the "big picture."

GENERAL HISTORICAL WORKS AND MONOGRAPHS: Move from the general to the specific. A book on the history of astronomy will provide more detail than a general text on European history. Try a keyword search at a larger library and you'll find dozens, if not hundreds, of books on the history of astronomy and related sciences. Another way to find secondary sources on your topic is to check the notes and bibliographies of books you've already found. And sometimes you might be able to find an entire book which is a bibliography on your topic; these books will be in the reference section, especially at university libraries.
Monographs are full-length books dealing with a relatively narrow topic and typically are intended for people with some background in the subject. Monographs typically rely on primary sources and are well-documented, with numerous citations.

JOURNAL ARTICLES: Historians don't always write books. Smaller essays on specific topics can be found in scholarly journals. These are periodicals similar to magazines, only they are specifically focused on history topics. Academic journals can usually be found at college and university libraries, and there are often indexes to help you find an article on a specific topic. Or just peruse some of these journals to see what kinds of questions professional historians are asking about your topic.