This collection contains papers of the related families of Michel Desravines Tesson and Thomas Forsyth. The bulk of the collection consists of correspondence, accounts, receipts, and bills relating to Thomas Forsyth's work as an Indian agent in Illinois in the early nineteenth century. The collection also contains papers relating to the genealogy of the Tesson, Forsyth, and related families; correspondence (mostly in French) of the Michel Desravines Tesson family and attorneys in France relating to the revolution in Santo Domingo and to family properties confiscated by the Haitian government after the revolution; and three daybooks of Thomas Forsyth with the Peorias, 1806-1816. This finding aid was compiled by keying in the document descriptions on the folder covers that were originally created by a Missouri Historical Society archivist in the mid twentieth century. In some cases these document descriptions contain direct quotes taken from the document; in other cases the descriptions comprise summaries or abstracts of the content of the document.