Suggestions from Archivist Lisa Rickey:
Selected public libraries
Selected historical societies
Selected county records centers
Note: You can also try county courthouses or offices for the location in question.
Selected colleges and universities
Unless otherwise noted, the resources linked below are available to WSU students, faculty, and staff because WSU has an institutional subscription.
Collections held in museums, national archives, university/college archives, and historical societies are often available. To check if any organization has done this for your topic, Google digital [or some version of this word] collections [your topic keywords] site:.edu (thanks to the Georgia State history librarian for putting this so well). You can also try site:.org (this would capture those by historical societies, for example) but remember that .org sites may be of poor quality--be sure to check who is sponsoring the website and what they are all about! Site:.gov will include U.S. government sites, including our national archives, Smithsonian institutions, and government departments.
The terms sources, documents, primary documents are sometimes useful to identify primary sources published in books or digitized on the internet, so you may also wish to try these terms if you are searching library catalogs or internet search engines for your topic.
As stated by Archivist Lisa Rickey, "Digital collections often reflect just a small fraction of the total holdings of a repository. There may be (and likely are) non-digitized materials at the same institution that are also pertinent to your research." Consider searching online finding aids to identify relevant non-digitized materials.
Note: If you cannot travel to the institution, inquire about the availability of research services and duplication services and any applicable fee(s). Fees can vary depending on the size and nature of the request.
Here are just a few examples of digitized collections.
A few examples of the digital archives in the Library of Congress collections that demonstrate the uniqueness of its digital memory.
The American Historical Association highlights digital primary sources at its annual meeting in the "Digital Projects Lightning Round".
In addition, the American Historical Review, the official journal of the American Historical Association, includes a Digital Primary Sources section in every issue (starting with April 2016). They ask readers to submit digital primary sources for inclusion.
Compiled by Archivist Lisa Rickey.