Series: 1 M (Volume 1)
Scope and Content Note

Original manuscripts, 1780-1791, of the elder William Clark. Most pertain to his service in the Illinois Regiment, his administration of the Illinois grant, and the development of the towns of Clarksville on the Mississippi River near Fort Jefferson in Kentucky and of Clarksville on the Ohio River in Indiana.

Numerous letters, 1782-1790, from John Girault in New Orleans and Natchez discuss economic conditions and relations with the Spanish in the lower Mississippi River Valley. Other correspondents include his father Benjamin Clark, Richard C. Anderson, John Armstrong, Philip Barbour, James Berwick, Daniel Brodhead, Richard Ruder, Abraham Chaplin, Valentine T. Dalton, John Dodge, John Edwards, James Harrod, Gilbert Imlay, Harry limes, John Montgomery, John Rogers, Arthur St. Clair, Robert Todd, John Williams, and John Wyllys.

Among signers of military and land records are Isaiah Boone, Richard Butler, George Rogers Clark, Worden Pope, Winthrop Sargent, and James Wilkinson. These documents include muster rolls, inventories of supplies, and lists of claimants and assignees to lots in Clark's grant.

Series: 2 M (Volume 2)
Scope and Content Note: Mainly additional papers, 1777 1793, of the elder William Clark, including correspondence; land survey notes; records pertaining to Clarksville, Indiana; and a few estate records after his death. Correspondents include John Armstrong, Abraham Chapline, Benjamin Clark, Andrew Heth, William Leas, James O'Fallon, John Rogers, Richard Terrell, John Thruston and George Walls. A few papers, 1814-1822, of the younger William Clark relate to midwestern Indian affairs. The majority are messages delivered in 1815 to representatives of the Chippewa, Kickapoo, Menominee, Potawatomi, and Sauk and Fox tribes signed by Clark, Auguste Chouteau, and Ninian Edwards, governor of Illinois Territory.

Series: 3 M (Volume 3)
Scope and Content Note: Letterbook, 1782-1789, kept by the elder William Clark, containing copies of outgoing letters. Although a few were addressed to his father Benjamin and to John Rogers and Buckner Thruston, most were written to John Girault. With the exception of personal messages to his father, all concern business affairs connected with the Illinois grant.

Series: 4 M (Volume 4)
Scope and Content Note: An account book, labeled “Ledger A,” 1784-1785, containing the elder William Clark's records for personal expenditures on clothing, food, and other supplies and for his work in surveying and administering the Illinois grant. The volume is prefaced by an index of the accounts prepared by Clark.

Series: 5 M (Volume 5)
Scope and Content Note: Daybook, 1787-1791, with a few pages of cash accounts, 1788-1791, kept by the elder William Clark at Clarksville, Indiana.

Series: 6 M (Volume 6)
Scope and Content Note: Charles Floyd's journal, May 14 - August 17, 1804, an original manuscript kept during the first weeks of the Lewis and Clark Expedition. Sergeant Floyd died two days after the last entry. A typewritten copy accompanies the manuscript. The diary was published in Reuben C. Thwaites, ed., Original Journals of the Lewis and Clark Expedition (New York, 1904-1905), VII, 3-26.