Biographical writings on Williamson; several memoranda written by Williamson pertaining to British, U.S., French, and Spanish relations; documents and proclamations written in Spanish; land deeds, receipts, legal papers; newspapers from the Ontario, Bath, and Genesee, New York areas; and a travel journal kept by Williamson while on a government mission in Turkey. The journal is quite detailed in describing his sea voyage, pirate encounters, and while in Turkey, the social and physical conditions of the country, including the food, music, villages, ceremonies, customs and human interactions while traveling on horseback throughout the country.