Army deserters and escaped slaves. 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in part below), although Harney actually commanded Military Department No. 5 for only three short periods, having been replaced by Colonel George N. Brooke on July 7, 1849; after Brooke's death from March 9 until September 15, 1851 when he was replaced by Colonel Persifor N. Smith, and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. 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. Harney briefly commanded troops during the Utah War and was again recalled and placed in command of troops sent to deal with the guerrilla warfare of Bleeding Kansas. Next, he was assigned command of the Department of Oregon. Harney sent Captain George E. Pickett and troops to San Juan Island, precipitating the Pig War with British forces. The Army recalled Harney to St. Louis after the altercations with the British. Promoted to brigadier general on June 14, 1858, Harney was, at 61, the youngest