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Primary Sources

This guide explains what primary sources are and demonstrates how to find them.

Introduction to find primary sources

Japan Strikes All Over Pacific


Boston Globe, December 8, 1941, the day after the attack on Pearl Harbor.


Primary sources can be found in a variety of places; you just have to know where to look! Most of this guide focuses on digital collections because you can use these resources from anywhere with access to the Internet. Digital collections are images of the original primary source, which should be acceptable for most school and college research.

Below, you will find some links to websites with digital collections. The tabs contain significant eras in United States history. This is not all that is available, but it can be a starting off point. If you are researching an event that is not in this guide, use the links below to research through the Boston Public Library and other digital collections.

What is a primary source?

The difference between a primary resource and other resources is the primary resource is an item that was made at the same time period you are researching - such as photographs, letters, and newspaper articles. Most of the items you have encountered in your research were probably created after the event - journal articles, books, and websites.

To decide if an item is a primary source, ask yourself two questions:

What time period or event am I researching?

When was this item originally created?

If those two questions have the same answer, it’s a primary source!

If you still have questions about whether your resource is a primary source or not, you can always ask for help. If you need it for an assignment, you can ask your teacher or professor. You can also ask your school, academic, or public librarian for help.

Example identifying primary sources:

What time period am I researching? World War II, 1939-1945
When were my items created? 2014 and 1942

When Books Went to War
This book is NOT a primary source. It was published in 2014, not in the time period we are researching. It could be a great resource, but it is not a primary source.
"Books are weapons in the war on ideas" poster.
This poster is a primary source! It was created in 1942, which is in the time period we are researching.