Google searches that locate digital collections, digital archives, digital repositories, and digital libraries tend to look something like:
"digital collections" site:.edu
"digital repository" site:.edu
"digital archives" site:.edu
Quotes are used to keep the phrase together and the command site:.edu focuses the Google search on university websites. You will need to vary the words to get various results – and – you will need to try both plural and singular word forms as well.
Since any one of these searches produces hundreds of thousands (or even millions) of results you will want to focus your search by either asking for the phrase “digital archive” (or digital collection or digital repository etc.) to appear in the title of the page … using the Google search command … intitle:”digital archive” … and/or add additional but very general words to select archives that might contain primary material on your topic.
For instance – if you're interested in finding more primary materials written by our about the Cherokee Indians during the late 18th and early 19th century – you might try the following Google searches:
intitle:"digital archive" Cherokee site:.edu
or you might try
intitle:"digital collection" Cherokee site:.edu
or you might try a more general search
intitle:"digital archive" “native American” site:.edu
or other variants such as
intitle:"digital collection" Cherokee Carolina site:.edu
(This last search leads to the Cherokee Phoenix (Newspaper) project which provides the text of Cherokee Nation newspaper articles from 1828 to 1831).
If instead you wish to locate digital archives or collections from local, state, or U.S. government sources – use the Google search command site:.gov
intitle:"digital collection" Cherokee Carolina site:.gov
LibGuides are websites - put together by librarians - that focus on particular topics. While some (much) of the content may be restricted to a particular campus or library - many LibGuides will also list free (open access) materials under categories such as "internet resources" - "websites" - "digital collections" - "digital libraries".
If I was looking for digital archives on the history Native Americans I might try various Google searches such as: