Search for your historic figure, then limit their name to author search. This will show materials they've written.
Be sure to limit the publication date range to their lifetime to limit false results.
William and Mary has over 500 primary source databases of which almost 200 include letters, diaries, and oral histories.
We also have newspapers from the early American period, most notably Early American Newspapers Series, 1-5, 1690-1922
Tips for searching primary sources
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