Question: Who led the Calvary at the Battle where Major Joel H. Elliott was a casualty ?

full_context: Document 1: Fort Mason, Arizona Territory: Following the Gadsden Purchase, the United States Army sent Major Enoch Steen and four companies of the 1st U. S. Dragoons (now the 1st U. S. Cavalry) to occupy the former site of the Mexican Presidio de Calabasas. Major Steen arrived on November 27, 1856, and named his post Camp Moore. The dragoons put roofs on the old adobe structures and added a few new ones. Camp Moore was abandoned in March 1857 after another location in the San Rafael Valley was chosen for a permanent fort that was christened Fort Buchanan. With the coming of the American Civil War all military posts in western New Mexico Territory (now Arizona) were abandoned. Old Camp Moore at Calabasas was briefly occupied by the Confederates in March 1862, just before the arrival of the California Column in April. The California Volunteers posted troops at Tucson and Tubac, and established Fort Bowie. In September 1865 the garrison at Tubac, Arizona was transferred to Old Camp Moore at Calabasas and it was named Fort Mason in honor of General Mason, who was commander of the California Volunteers. The 1st Battalion of Native Cavalry, California Volunteers and 7th Regiment California Volunteer Infantry occupied the post until they were relieved by troops of the United States Army in May 1866. Due to persistent malaria, the Regulars abandoned Fort Mason in October 1866 and established Camp Cameron. Camp Moore and Fort Mason were collocated south of the confluence of Potrero Creek and the Santa Cruz River. Camp Cameron was about 16 miles northeast of Fort Mason and existed from October 1, 1866 to March 7, 1867.
Document 2: Fort C. F. Smith (Fort Smith, Montana): Fort C. F. Smith was a military post established in the Powder River country by the United States Army in Montana Territory on August 12, 1866, during Red Cloud's War. Established by order of Col. Henry B. Carrington, it was one of five forts proposed to protect the Bozeman Trail against the Oglala Lakota (Sioux), who saw the trail as a violation of the 1851 Treaty of Fort Laramie . The fort was abandoned in 1868 and burned by the Sioux under Red Cloud.
Document 3: Jesse L. Reno: Jesse Lee Reno (April 20, 1823 – September 14, 1862) was a career United States Army officer who served in the Mexican–American War, the Utah War, the western frontier, and as a Union General during the American Civil War. Known as a "soldier's soldier" who fought alongside his men, he was killed while commanding a corps at Fox's Gap during the Battle of South Mountain. Reno County, Kansas, El Reno, Oklahoma, Reno, Nevada, Reno, Pennsylvania and Fort Reno in Washington, D.C. were named after him.
Document 4: Red River War: The Red River War was a military campaign launched by the United States Army in 1874 to remove the Comanche, Kiowa, Southern Cheyenne, and Arapaho Native American tribes from the Southern Plains and forcibly relocate them to reservations in Indian Territory. Lasting only a few months, the war had several army columns crisscross the Texas Panhandle in an effort to locate, harass, and capture highly mobile Indian bands. Most of the engagements were small skirmishes in which neither side suffered many casualties. The war wound down over the last few months of 1874, as fewer and fewer Indian bands had the strength and supplies to remain in the field. Though the last significantly sized group did not surrender until mid-1875, the war marked the end of free-roaming Indian populations on the southern Great Plains.
Document 5: Red River Canyon affair: The Red River Canyon affair, or the Battle of Red River Canyon, was a military action fought during the Taos Revolt of the Mexican-American War. Although the Americans mistakenly called this river by the name "Red", it was actually then and now more correctly called the Canadian River. On 26 May 1847, a detachment of American troops, traveling through northern New Mexico, were attacked by a combined force of Mexican militia with their Apache, Kiowa, and Comanche allies.
Document 6: Fort Elliott: Fort Elliott was a United States Army post in the Texas Panhandle, operational between 1875 and 1890 and named for Major Joel H. Elliott, a casualty of the Battle of Washita River in 1868.
Document 7: Powder River Massacre: The Powder River Massacre, part of the Powder River Expedition, occurred on August 17, 1865, and was carried out by United States soldiers and Pawnee scouts against 24 Cheyenne people. The incident occurred near the Powder River in Dakota Territory, in present-day Johnson County, Wyoming.
Document 8: Red Cloud's War: Red Cloud's War (also referred to as the Bozeman War or the Powder River War) was an armed conflict between the Lakota, Northern Cheyenne, and Northern Arapaho on one side and the United States in Wyoming and Montana territories from 1866 to 1868. The war was fought over control of the western Powder River Country in present north-central Wyoming. This grassland, rich in buffalo, was traditionally Crow Indian land, but the Lakota had recently taken control. The Crow tribe held the treaty right to the disputed area, according to the major agreement reached at Fort Laramie in 1851. All involved in "Red Cloud's War" were parties in that treaty.
Document 9: Ambush of the steamboat J. R. Williams: The ambush of the steamboat "J.R. Williams" was a military engagement during the American Civil War. It took place on May 10, 1864 on the Arkansas River in Indian Territory which became encompassed by the State of Oklahoma. It is popularly termed the "only naval battle" in that landlocked state. It was a successful Confederate attack on the Union Army's lines of supply. The Confederate forces were Cherokee, Chickasaw, Choctaw and Creek Indians led by General Stand Watie, who was a Cherokee.
Document 10: Buffalo Calf Road Woman: Buffalo Calf Road Woman, or Brave Woman (c. 1850s? – 1879), was a Northern Cheyenne woman who saved her wounded warrior brother, Chief Comes in Sight, in the Battle of the Rosebud (as it was named by the United States) in 1876. Her rescue helped rally the Cheyenne warriors to win the battle. She fought next to her husband in the Battle of the Little Bighorn that same year. In 2005 Northern Cheyenne storytellers broke more than 100 years of silence about the battle, and they credited Buffalo Calf Road Woman with striking the blow that knocked Lieutenant Colonel George Armstrong Custer off his horse before he died.
Document 11: Battle of Fort Titus: In August 1856 Camp Sacket, a U.S. Army post, was about a mile away from Fort Titus. Fort Saunders, some distance south of Fort Titus, was destroyed by free-state partisans on August 15, 1856. Fort Titus was attacked the next day. This was the Battle of Fort Titus. About 400 free-staters under the command of Samuel Walker attacked Fort Titus. Titus had a force of at least twenty-one men, including thirteen German stonemasons from nearby Lecompton, Kansas, with him. The attack was launched before a brass cannon had arrived on the site. This attempt was unsuccessful and the leader of this first attack was killed. Apparently some of the men from this attack placed themselves between Lecompton and the Army troops, so no messages could be sent between Wilson Shannon, the governor, and the troops.
Document 12: Battle of Appomattox Station: The Battle of Appomattox Station was fought between a Union Army (Army of the Potomac, Army of the James, Army of the Shenandoah) cavalry division under the command of Brigadier General (Brevet Major General) George Armstrong Custer and Confederate Army of Northern Virginia artillery units commanded by Brigadier General Lindsay Walker with support from some dismounted cavalrymen, artillerymen armed with muskets and some stragglers on April 8, 1865, at Appomattox Station, Virginia during the Appomattox Campaign of the American Civil War.
Document 13: Battle of Washita River: The Battle of Washita River (also called Battle of the Washita or the Washita Massacre) occurred on November 27, 1868 when Lt. Col. George Armstrong Custer’s 7th U.S. Cavalry attacked Black Kettle’s Southern Cheyenne camp on the Washita River (near present-day Cheyenne, Oklahoma), part of a major winter encampment of numerous Native American tribal bands.
Document 14: Fort Reno (Oklahoma): Fort Reno is a former United States Army cavalry post west of El Reno, Oklahoma. It is named for General Jesse L. Reno, who died at the Battle of South Mountain in the American Civil War.
Document 15: Fort Harker (Kansas): Fort Harker, located in Kanopolis, Kansas, was an active military installation of the United States Army from November 17, 1866 to October 5, 1872. The fortification was named after General Charles Garrison Harker, who was killed in action at the Battle of Kennesaw Mountain in the American Civil War. Fort Harker replaced Fort Ellsworth, which had been located 1.6 km from the location of Fort Harker and was abandoned after the new fortifications at Fort Harker were constructed. Fort Harker was a major distribution point for all military points farther west and was one of the most important military stations west of the Missouri River.
ground_truth: Lt. Col. George Armstrong Custer