William Clarke, an American soldier, born in Virginia, Aug. 1, 1770, died in St. Louis, Mo., Sept. 1, 1838. In 1784 his father removed to Kentucky, and settled on the present site of the city of Louisville. Young Clarke early became acquainted with Indian warfare, and at the age of 18 he was appointed ensign and went into active service; and on March 7, 1792, he became a lieutenant of infantry. Appointed adjutant and quartermaster in 1793, he served till July, 1796, when he resigned on account of ill health. He soon after took up his residence in St. Louis, and in 1803 was appointed by President Jefferson second lieutenant of artillery, with orders to assume, in connection with Capt. Meriwether Lewis, the command of an exploring expedition across the Rocky mountains to the mouth of the Columbia, which left St. Louis in March, 1804. Clarke was the principal military director of the expedition, while he also rendered material assistance to Capt. Lewis in the scientific arrangements. It was to his consummate knowledge of Indian habits and manners that the expedition owed its success, He was promoted to the rank of first lieutenant in January, 1806. The nomination of lieutenant colonel, offered him by the government, was negatived by the senate, and resigning, Feb. 27, 1807, he officiated as Indian agent till he was appointed by congress brigadier general for the territory of Upper Louisiana. In 1813 President Madison appointed him governor of the Missouri territory, which post he held until the organization of Missouri as a state in 1821, when, being nominated against his consent for governor of the state, he was defeated.

In May, 1822, President Monroe appointed him superintendent of Indian affairs, which office he held till his death.