Soldier and explorer (1770–1838) who, with Meriwether Lewis, undertook a two-year expedition in 1804 to discover a navigable route to the Pacific Ocean, in the process exploring and later describing much of the course along the Missouri River. Following the expedition, Clark resumed his military career, serving as agent for Indian affairs in St. Louis and leading a number of campaigns during the War of 1812. Scarce manuscript DS, signed “Wm. Clark,” one page, 7.5 x 7.5, April 27, 1814. A receipt for military rations. In part: “Provision return for eighty eight men of Capt. Yeiser’s[?] command now in service of the United States for one day commencing Apl. 27th and ending same day…. The contractor will issue one hundred and thirty two complete rations agreeable to the above return….” Light intersecting folds (vertical fold to last name; a few short edge separations) and losses to blank corners (very slightly touching one letter of text), otherwise fine condition. Auction LOA John Reznikoff/PSA/DNA and R&R COA.