William Clark (1770-1838), born in Caroline County, Virginia, moved to Kentucky with his family when he was 15 years old. He served in the militia on the frontier beginning in 1789 and became a lieutenant in the regular army three years later. He resigned that commission in July 1796 to manage his family’s assets, which included land, slaves, and a mill, and to contend with the substantial debts of his older brother, George Rogers Clark. In 1802, William Clark sold the family’s tobacco plantation in Kentucky and moved into a modest dwelling with his brother at Clarksville or Clark’s Point, across the Ohio River from Louisville. He was acquainted with much of the frontier of the United States, having traveled for the army or on business trips to Vincennes, Kaskaskia, Spanish posts on the Mississippi River, Chickasaw territory, Ste. Genevieve, St. Louis, New Madrid, and New Orleans. He lacked formal education but read works of philosophy, literature, history, and science, and in his travels he had developed a skill of observing details that he recorded in notebooks and journals. TJ later appointed him Indian agent of Louisiana Territory and brigadier general of the territory’s militia. In Madison’s presidency he became governor of Missouri Territory. Clark married Julia (Judith) Hancock in 1808. Following her death in 1820, he married a widowed relative of hers, Harriet Kennerly Radford (ANB description begins John A. Garraty and Mark C. Carnes, eds., American National Biography, New York and Oxford, 1999, 24 vols. description ends ; Landon Y. Jones, William Clark and the Shaping of the West [New York, 2004], 50-2, 55-7, 66-7, 70-1, 89-110, 112, 142, 155, 262; William E. Foley, Wilderness Journey: The Life of William Clark [Columbia, Mo., 2004], 24, 41-2, 48, 52; Heitman, Dictionary description begins Francis B. Heitman, comp., Historical Register and Dictionary of the United States Army, Washington, D.C., 1903, 2 vols. description ends , 1:306).

assureance of your approbation: Lewis had written to Clark on 19 June asking him to join the transcontinental expedition. The two of them had become acquainted at Fort Greenville in the Northwest Territory in 1795, when Lewis was an ensign in the army and Clark a lieutenant. In the fall of that year, General Anthony Wayne assigned Lewis to a rifle company commanded by Clark. Several months later Clark left the army, but he and Lewis maintained their acquaintance. Clark also traveled through Washington, meeting TJ there in 1801 (Jackson, Lewis and Clark description begins Donald Jackson, ed., The Letters of the Lewis and Clark Expedition, with Related Documents, 1783-1854, 2d ed., Urbana, Ill., 1978 description ends , 1:57-60; 2:572; Foley, Wilderness Journey, 39-40; Jones, William Clark, 108, 113; Vol. 40:172).