A common misconception about library collections is that everything is online. Actually, however, although there are millions of digitized primary sources online and more content is added every day, the vast majority of unpublished archival material that exists in libraries, archives, museums, and historical societies around the world has not been digitized and is not available online.

That said, in-depth research is still possible because libraries have made whole collections available online where once they could offer only highlights. But you might be wondering why some materials are digitized while others are not. Following are a few of the reasons:

Some items, like documents in national archives, may be considered to have high research value for a wide audience. Or collections might be in high demand locally and the originals could be at risk of damage from overuse.

Collections that belonged to a well-known person or organization might be deemed important because of their provenance and thus find their way online. Or they might be visually compelling. Photographs and other images are more dazzling than handwritten documents, generally speaking, and are often featured prominently in online portals.

Another common reason for digitizing is preservation. When documents are too fragile to use, they might be microfilmed and/or digitized to preserve access to the information. Sometimes materials are given to a library along with funds to process and digitize them. Grant funding has made possible much of the digitizing that has been undertaken in libraries, archives, museums, and historical societies. Repositories may collaborate on grant applications and then present their digitized holdings together in online portals.

There can be a commercial motive too. Vendors today digitize previously microfilmed archival collections, historical periodicals, and government documents, add bells and whistles, and market them to libraries in subscription databases.

Following are examples of some amazing open access primary source collections and portals you can find online. See our Archival Research Guide for more information and research tips.

• Umbra Search – African American History
• Endangered Archives Programme
• Tulane University Digital Library
• 1964 Freedom Summer Project

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