The Samuel Sitgreaves papers contain 13 letters written by Sitgreaves during travels around England, France, and the Netherlands. Ten items date from March to November of 1800; Sitgreaves likely also wrote the collection's three undated items during this period, while serving as U.S. commissioner to Great Britain. Sophia Kemper, Sitgreaves' sister-in-law, was the recipient of at least nine of the letters, while two items are Sitgreaves' retained copies of letters to fellow Pennsylvania politician, Thomas FitzSimons. Timothy Pickering is the recipient of an additional letter. Most of the letters are fragmentary, but still substantial.
Letters to Kemper contain rich details of daily life and travel, as well as observations on European society and politics. Two letters describe Sitgreaves' journey from London to Calais, including topics such as the necessity of bribing French officials (May 20, 1800), the sick and dying French expatriates on his ship, and his observations of the scantily-clad peasant women of Calais, which he found "at once distressing and disgusting beyond measure" (May 27, 1800). In many of the letters, he expressed surprise at the poverty of the French and English populations, and particularly the "universal suffering" of the inhabitants of London (November 8, 1800). In other letters, Sitgreave reflected on particular topics, including the English theater, which he attended four nights per week (October 17, 1800) and the State Opening of Parliament by King George III (November 16, 1800).
Sitgreaves' correspondence to FitzSimons relates to foreign relations with France and Great Britain and the ongoing issues arising from the Jay Treaty. In a letter of August 7, 1800, Sitgreaves translated for FitzSimons his letter to the Doctrina et Amicitia , a Dutch patriot society, in which he described the "three Points constitut[ing] the Subject of the Negotiations" with France. In another letter, dated August 12, 1800, he further discussed the group, as well as negotiations with the French regarding ports and asylum, and his suspicions about their motives and desire to influence American politics.