Question: In which battle did the Uncle of Henry Armstrong Reed and youngest brother of a US Army Lt Colonel and a two-time Medal of Honor Recipient get killed along with his brothers and his nephew? 

full_context: Document 1: Warren Earp: Warren Baxter Earp (March 9, 1855 – July 6, 1900) was the youngest brother of Wyatt, Morgan, Virgil, James, and Newton Earp. Although he was not present during the Gunfight at the O.K. Corral, after Virgil was maimed in an ambush, Warren joined Wyatt and was in town when Morgan was assassinated. He also helped Wyatt in the hunt for the outlaws they believed responsible. Later in life, Warren developed a reputation as a bully and was killed in an argument in 1900.
Document 2: Moving Robe Woman: Moving Robe Woman (Sioux name Tȟašína Máni), also known as Mary Crawler, Her Eagle Robe, She Walks With Her Shawl, and Walking Blanket Woman, was a Hunkpapa Sioux woman who fought against Custer during the Battle of Little Big Horn to avenge her brother, One Hawk, who had been killed. Her father's name was Crawler, and he was also present at the battle. An Oglala Lakota warrior named Fast Eagle claimed that he had held Custer's arms while Moving Robe Woman stabbed him in the back, but several other warriors claimed to have killed Custer, so it is uncertain if she actually killed him, especially since there are no published post-mortem accounts that describe Custer as having stab wounds, and because officers who found his body described him as having died of gunshot wounds.
Document 3: Shooting of Gareth Hutch: Gareth Hutch was shot dead on Tuesday 24 May 2016. He was a nephew of Gerry Hutch. He was also a cousin of Gary Hutch and a nephew of Eddie Hutch Snr.
Document 4: 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 5: George Armstrong Custer: Custer developed a strong reputation during the Civil War. He participated in the first major engagement, the First Battle of Bull Run on July 21, 1861, near Washington, D.C. His association with several important officers helped his career as did his success as a highly effective cavalry commander. Custer was brevetted to brigadier general at age 23, less than a week before the Battle of Gettysburg, where he personally led cavalry charges that prevented Confederate cavalry from attacking the Union rear in support of Pickett's Charge. He was wounded in the Battle of Culpeper Court House in Virginia on September 13, 1863. In 1864, Custer was awarded another star and brevetted to major general rank. At the conclusion of the Appomattox Campaign, in which he and his troops played a decisive role, Custer was present at General Robert E. Lee's surrender to General Ulysses S. Grant, on April 9, 1865.
Document 6: Dewey Beard: Dewey Beard or Wasú Máza ("Iron Hail", 1858–1955) was a Minneconjou Lakota who fought in the Battle of Little Bighorn as a teenager. After George Armstrong Custer's defeat, Wasu Maza followed Sitting Bull into exile in Canada and then back to South Dakota where he lived on the Cheyenne River Indian Reservation. Chief Iron Hail is often mistaken by historians for Chief Iron Tail, being Lakota contemporaries with similar-sounding names. Most biographies incorrectly report that Chief Iron Tail fought in the Battle of the Little Bighorn and that his family was killed in 1890 at Wounded Knee, when in truth it was Chief Iron Hail who suffered the loss.
Document 7: Joseph Horn Cloud: Joseph Horn Cloud born 1873 and died September 18, 1920. His father was Horn Cloud and mother Nest, both parents died at the Wounded Knee Massacre along with two brothers William Horn Cloud (1876-1890), Sherman Horn Cloud (1865-1890) and a niece. Joseph was a survivor of the massacre as well as his brother Daniel and half brother Dewey Beard [p. 89-95]. Dewey's mother was Yellow Leaf who also died during the massacre. In the early 1900s a writer named Eli S. Ricker began research for a book he was going to call "The Final Conflict between the Red Men and the Palefaces." He gathered sources and interviews about conditions and battles on the Plains during the last half of the 1800s. He recorded the interviews in small note pads known to historians as the "Ricker Tablets." One such interview was with Joseph telling Ricker what he witnessed at the Wounded Knee Massacre, "When the shooting began the women ran to the ravine. The shooting was in every direction. Soldiers shot into one another... Many of the Indians in the circle were killed. Many of them mingled with the soldiers behind them, picking up guns from dead soldiers and taking cartridge belts."
Document 8: Boston Custer: Boston Custer (October 31, 1848 – June 25, 1876) was the youngest brother of U.S. Army Lt Colonel George Armstrong Custer and two-time Medal of Honor recipient Captain Thomas Custer. He was killed at the Battle of the Little Bighorn along with his two brothers.
Document 9: Little Hawk (Crazy Horse's brother): Little Hawk (1842-1871) is the younger half brother of the famous Oglala warrior Crazy Horse # 3 (1840- 1877). He was the offspring of the remarriage of Worm, Crazy Horse's # 2 widowed father, to a pair of sisters of the Brulé Lakota chief Spotted Tail, Iron Between Horns and Kills Enemy.
Document 10: Custer Monument (West Point): Custer Monument is a monument at the United States Military Academy Cemetery, in honor of Lieutenant Colonel George Armstrong Custer who was killed along with his immediate command at the Battle of the Little Bighorn on 25 June 1876. Congress approved of a statue, to be made from 20 condemned bronze canons, and for $10,000, of which $6,000 had been subscribed by citizens of New York. The monument was originally located near the academy's headquarters building near the site of present day Taylor Hall along Thayer Road. Unveiled in 1879, the pedestal had a bronze statue of Custer wielding a saber and a pistol. Custer's widow and many officers did not approve of this likeness and after only five years, the statue was removed and sent to New York City where Stanford White was supposed to remove the bust, to be displayed in the library. However after White's murder, its whereabouts have since been lost. The pedestal was moved to Custer's grave site in the West Point Cemetery during the construction of Taylor Hall around 1910. In 1965, a stone obelisk was placed atop the pedestal.
Document 11: Louis McLane Hamilton: Louis McLane Hamilton (1844–1868) was an officer in the United States Army during and after the American Civil War. He served as a captain under General George Armstrong Custer in the Indian Territory in present-day Oklahoma, where he died at the age of 24 while leading a charge in the Battle of Washita River. He was a grandson of Alexander Hamilton, one of the Founding Fathers of the United States.
Document 12: Henry Armstrong Reed: Henry Armstrong Reed (April 27, 1858 – June 25, 1876) was the nephew of George Armstrong Custer, Thomas Custer, and Boston Custer. Although not an official soldier, he was killed along with them at the Battle of the Little Bighorn at the age of 18.
Document 13: 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 14: Thomas Custer: Thomas Ward Custer (March 15, 1845 – June 25, 1876) was a United States Army officer and two-time recipient of the Medal of Honor for bravery during the American Civil War. He was a younger brother of George Armstrong Custer's, and perished with him and their younger brother, Boston Custer, at Little Bighorn in the Montana Territory.
Document 15: Crow King: Crow King (in Lakota Kȟaŋǧí Yátapi), also known as Medicine Bag That Burns, Burns The Medicine Bag or simply Medicine Bag; was a Hunkpapa Sioux war chief at the time of the Battle of Little Big Horn. Crow King was one of Sitting Bull's war chiefs at the Battle, he led eighty warriors against Custer's men on Calhoun Hill and Finley Ridge. For the duration of the battle of Little Bighorn, Crow King and his band of eighty warriors attacked Custer from the south, allowing Crazy Horse and Gall to surround the 7th Cavalry. Crow King died in 4-5-1884, cause of death according to the 4-11-1884 Bismarck Tribune, he died of "quick consumption" from a long lasting cold and received the rites and sacraments of the Catholic Church. Location of his burial is unknown.
ground_truth: Battle of the Little Bighorn