William Clark kept this diary on an expedition to make a treaty with the Osage Indians in the Missouri Territory. A sketch drawn under the September 16 entry is apparently a draft of Clark's Fort Osage map, while the first page of notes presents color scheme used on another draft. See Kate L. Gregg, Westward with Dragoons (1937: 48) for the map in printed version.

The first volume includes extracts from the journals of Conrad Weiser and Christian Frederick Post (1757), Charles Thomson's "An Enquiry into the causes of the alienation of the Delaware and Shawanese Indians from the British interest" (1759), and a printed version of Judge Bradford's "Statement of facts and observations respecting the penal laws" (1792). The second volume contains selected letters and documents in the Pennsylvania state records on Indian relations, including transcriptions of several treaties between the Province of Pennsylvania and the Delawares and other Indians (1755-1758); the French and Indian War; and Braddock's campaign. Some manuscripts are written by Deborah Norris Logan and Charles Thomson.