In 1817, Harney's brother, Dr. Benjamin F. Harney, an Army surgeon in
Baton Rouge, Louisiana, asked
Andrew Jackson, a hero of the
War of 1812 and the current commander of the Army of the South, to write a letter to the Secretary of the Navy to ask for Harney's acceptance into the Navy, which occurred July 23, 1817. Harney visited his brother and met high-ranking military officers. He so impressed them that they arranged a commission for him as a
U.S. Navy second lieutenant, which President
James Monroe signed. However, Harney chose to serve under Jackson in the army. His first military assignment under Jackson was in 1818, as a second lieutenant in the
1st U.S. Infantry. He helped to force the pirate
Jean Lafitte to move his operations from the
Louisiana Territory to the
Spanish Main. There he met, fought, and befriended Jefferson Davis, Taylor's son-in-law and a fellow army officer.
Murder of Hannah In June 1834, while he was a major in the Paymaster Corps,
Jefferson Barracks,
St. Louis, Missouri, Harney was charged with beating an enslaved woman, Hannah, to death. The keys for Harney's office became lost, Harney suspected Hannah of taking them and in a fit of anger he savagely beat her with a piece of
rawhide, with the woman dying three days later; Harney then fled to avoid arrest, while seeking a transfer to another state. This was not the only instance of Harney brutalizing slaves. He owned a group of muscular male slaves whom he enjoyed provoking into fistfights with soldiers.
Second Seminole War During the
Second Seminole War (1835–1842), Harney gained a reputation as an Indian fighter for daring and ruthless raids.
Mexican–American War During the
Mexican–American War, Harney was appointed
colonel and commanded the 2nd Dragoons. However, President
James K. Polk overrode Scott's judgment to remove Harney from command and concluded that Harney's only fault was being in the
Democratic Party. The incident damaged the relationship between the general and Commander-in-Chief. Placed in temporary command of the 1st Brigade in
David Twiggs's division, Harney fought with distinction at the
Battle of Cerro Gordo and received a promotion to
brevet brigadier general. He returned to cavalry command during the
Battle of Contreras, the
Battle of Churubusco, and the
Battles for Mexico City. However, he was accused of mistreatment of captured prisoners from the
St. Patrick's Battalion, which included US Army deserters and escaped slaves. ) By order of Gen.
Winfield Scott, thirty were to be executed at the
Battle of Chapultepec in full view of the two armies, and at the precise moment that the flag of the U.S. replaced the flag of Mexico atop the citadel. Harney was ordered to carry out the execution but was taunted and jeered by the condemned men. One of the condemned, Francis O'Connor, was ordered by Harney to be hanged even though both his legs had been amputated the previous day. When the army surgeon informed Colonel Harney that the absent soldier had lost both his legs in battle, Harney was said to have replied: "Bring the damned son of a bitch out! My order was to hang 30 and by God I'll do it!" In the aftermath of the executions, it was reported that Harney refused to cut the bodies down, stating that "I was ordered to have them hanged, and have no orders to
unhang them". Harney became an original member of the
Aztec Club of 1847, which was composed of American officers who had served in Mexico.
First Sioux War On May 14, 1849, on the death of Brevet Major General
William J. Worth, Harney assumed command of Military Department Number Five, which comprised almost all of the settled portion of
Texas. He was assigned to control Indian raids, which led to the
First Sioux War (discussed in part below), although Harney actually commanded Military Department No. 5 for only three short periods, having been replaced by Colonel George N. Brooke on July 7, 1849; after Brooke's death from March 9 until September 15, 1851, when he was replaced by Colonel Persifor N. Smith, and then from December 3, 1852, until he was again relieved by Smith on May 11, 1853. Recalled from leave after he had attempted to visit his family in Paris in 1854, Harney led a punitive expedition against the
Sioux after they killed a small US Army detachment in
Nebraska Territory, an event called the
Grattan massacre. He led attacks against the
Brulé Lakota, who were involved in conflicts with immigrant travelers on the
Oregon Trail. In the
Battle of Ash Hollow, on September 2 and 3, 1855, Harney's troops routed
Little Thunder's village at Blue Water Creek (now known as
Ash Hollow), in western Nebraska, killing about half of the 250 band members. Among the victims were women and children who had hidden in a cave, into which cannons were fired under the pretense that they were warriors. Following this massacre the Sioux gave Harney the nicknames of “The Butcher” and “The Big Chief who Swears”. Harney earned a Lakota name translated as "Mad Bear" because after the attack, he marched across the Badlands to
Fort Pierre, the largest trading post in
Dakota Territory, and challenged the Lakotas to a winter fight. The success of the campaign encouraged Harney to suggest that mobile units might replace permanent army posts. The Army recalled Harney to St. Louis after the altercations with the
British. Promoted to brigadier general on June 14, 1858, Harney was, at 57, the youngest of the four general officers in the regular army at the time, (alongside the War of 1812 veterans
Winfield Scott,
John Wool, and
David Twiggs, the next-youngest, at 70, because of the lack of a fixed retirement age). ==American Civil War==