There are many primary sources but I found these most helpful:
Adams, A., Cranch, M. S., & Mitchell, S. (1947). New letters of Abigail Adams, 1788-1801. Houghton Mifflin Co.
Adams, J. (1961). Diary and Autobiography of John Adams. Harvard University Press.
Adams, J. Q. The Diary of John Quincy Adams. Massachusetts Historical Society. https://www.masshist.org/jqadiaries/php/
Diary and letters of Rutherford Birchard Hayes, nineteenth president of the United States. Freemont, OH: The Ohio State Archaeological and Historic Society.
The Papers of James Monroe, 7 volumes (D. Preston & C. Good, Eds. Vol. 1). Greenwood Press.