Remember that academic libraries use the Library of Congress Classification System and subject headings. Once you find a good subject heading, you can find all the items in a library on that topic.
So -- be sure to look at the full record and use keywords from the subject headings to do another search or you may see the perfect subject heading that you can just click on.
- correspondence
- presidents and correspondence
- soldiers and correspondence
- diaries
- personal narratives
- speeches, addresses, etc.
- campaign speeches
- autobiography - make sure it really is an autobiography
- memoir - make sure it really is a memoir
- sources- Adding the word "sources" to your search will many times get you primary documents. It doesn't always work but often enough to be extremely useful -- and, it leads you to sources that will tell you about primary sources and give you citations and locations.