William Selby Harney, born in Tennessee in 1800, entered the United States Army as a lieutenant at age seventeen. Like many officers, he learned on the job, and in some ways he resembled the stereotypical, hell-raising, blood-and-guts, Indian-fighter of modern-day novelists and movie makers. He was quarrelsome, quick-tempered, and sometimes vicious, and his frequent bickering typified the entire officer corps. After years of routine duty, in 1829 Harney participated in the Atkinson Expedition against Arikara Indians on the upper Missouri River. Promoted to captain, he performed garrision duty in the Old Northwest and in 1832 fought in the Black Hawk War. In 1833 Harney married Mary Mullanphy of St. Louis and secured a paymaster's appointment and major's rank. He failed at this job, though, and in 1834 murdered a slave. He avoided punishment and in 1836 was appointed lieutenant colonel in the Second Dragoons. Subsequently Harney earned widespread recognition for effective Indian campaigns. During the Second Seminole War he developed new amphibious riverine tactics. During the Mexican War his attack on Cerro Gordo prepared the way for American capture of Mexico City. Afterward in Texas, he advocated using more mounted troops against plains Indians. In 1855-56 he decisively defeated the Sioux in Nebraska and set precedents for future army operations. In the 1850s Harney helped maintain civil order in "Bleeding" Kansas and in Utah, where Mormons resisted federal authority. He was subsequently promoted to brigadier general, but the remainder of his career proved frustrating. While commanding the Department of Oregon in 1859, he almost thrust America into war with Great Britain by occupying jointly claimed San Juan Island. In 1861, while commanding the Department of the West, he failed to take firm action to assure Union control of Missouri, and that called into question his loyalty to the Union. President Lincoln removed him from command. Harney's career illustrates both the army's successes and its failures in facilitating westward expansion and suggests that the military performed as well as it could with its limited resources. Harney died in 1889.