Question: What tribe what American Horse a part of?

Context paragraphs:
Maryland Horse Industry Board: The Maryland Horse Industry Board (MHIB) is an agency which is part of the Maryland Department of Agriculture in the United States.  The MHIB, originally the State Board of Inspection of Horse Riding Stables, was established by Maryland statute in 1968.  It was made part of the Department of Licensing and Regulation in 1970.  The Board transferred to the Department of Agriculture in 1980.  In October 1998 the duties and name of the MHIB were altered.  The change resulted from a statutory change lobbied for by the Maryland Horse Council, a member organization of the American Horse Council.  The duties of the MHIB expanded beyond stable licensing to include:

Havre de Grace (horse): Havre de Grace (foaled on May 12, 2007, in Kentucky) is an American Thoroughbred Racehorse who was 2011 American Horse of the Year.  During her racing career, she was owned by Fox Hill Farms and trained by J. Larry Jones.  Her sire is the 2005 American Horse of the Year, Saint Liam.  Her dam is the mare Easter Bunnette, a daughter of Carson City.  Her name derives from the city and racetrack of Havre de Grace, Maryland.

John Wallace Crawford: John Wallace ("Captain Jack)" Crawford (1847–1917), known as "The Poet Scout", was an American adventurer, educator, and author.  "Captain Jack" was a master storyteller about the Wild West and is known in American history as one of the most popular performers in the late nineteenth century.  His daring ride of 350 miles in six days to carry dispatches to Fort Laramie for the "New York Herald", to tell the news of the great victory by Gen. George Crook against the village of Chief American Horse at the Battle of Slim Buttes during the Great Sioux War of 1876-1877, made him a national celebrity.

Lucky Pulpit: Lucky Pulpit (foaled February 10, 2001– February 13, 2017) was an American Thoroughbred stallion who stood at Harris Farms in Coalinga, California.  Lucky Pulpit was a son of the Blue Grass Stakes winner Pulpit, and grandson of the 1992 United States Horse of the Year A.P. Indy.  Although his own racing career was limited due to respiratory issues, Lucky Pulpit was best known as the sire of California Chrome, two-time American Horse of the Year, winner of the 2014 Kentucky Derby and 2014 Preakness Stakes and all-time leading North American horse in earnings won.  At the time of Lucky Pulpit's death in 2017, he had sired 148 winners from 229 starters and was credited with progeny earnings of $24 million.

California Chrome: California Chrome (foaled February 18, 2011) is an American Thoroughbred racehorse.  He was named the 2014 and 2016 American Horse of the Year.  He won the 2014 Kentucky Derby, the Preakness Stakes, and the 2016 Dubai World Cup.  In 2016, he surpassed Curlin as the all-time leading North American horse in earnings won.

American Horse Council: The American Horse Council (AHC) is a trade organization in Washington, DC representing the horse industry.  The organization formed in 1969, with a committee that became the Coalition of State Horse Councils forming in 1970, now having 43 states participating.  American Horse Council Foundation was founded in 1991.

American Horse: American Horse (Oglala Lakota: "Wašíčuŋ Tȟašúŋke" in Standard Lakota Orthography) (a/k/a "American Horse the Younger") (1840 – December 16, 1908) was an Oglala Lakota chief, statesman, educator and historian.  American Horse is notable in American history as a U.S. Army Indian Scout and a progressive Oglala Lakota leader who promoted friendly associations with whites and education for his people.  American Horse opposed Crazy Horse during the Great Sioux War of 1876-1877 and the Ghost Dance Movement of 1890, and was a Lakota delegate to Washington.  American Horse was one of the first Wild Westers with Buffalo Bill’s Wild West and a supporter of the Carlisle Indian Industrial School.  “His record as a councillor of his people and his policy in the new situation that confronted them was manly and consistent and he was known for his eloquence."

George Conway: George H. Conway (? -1939) was a Triple Crown-winning American horse trainer who worked at Glen Riddle Farm in Berlin, Maryland.  He is best known for training War Admiral, who won the Triple Crown in 1937 and was selected as the American Horse of the Year over his nephew and competitor Seabiscuit.  Other notable horses trained by Conway include American Flag, who won the Belmont Stakes in 1925 before training with Conway, Crusader, who won the 1926 Belmont Stakes with Conway, and War Relic, who was the last horse that Conway trained.

United States Equestrian Federation: The United States Equestrian Federation (USEF or US Equestrian) is the national governing body for most equestrian sports in the United States.  It began on January 20, 1917, as the Association of American Horse Shows, later changed to the American Horse Shows Association (AHSA).  In 2001, the organization changed its name to USA Equestrian (USAE) and, in 2003 it merged with the United States Equestrian Team (USET).  In 2017, USEF rebranded as US Equestrian.

American Horse (elder): American Horse (Oglala Lakota: "Wašíčuŋ Tȟašúŋke" in Standard Lakota Orthography) (a/k/a "American Horse the Elder") (1830–September 9, 1876) was an Oglala Lakota warrior chief renowned for Spartan courage and honor.  American Horse is notable in American history as one of the principal war chiefs allied with Crazy Horse during Red Cloud's War (1866–1868) and the Battle of the Little Bighorn during the Great Sioux War of 1876-1877.  Chief American Horse was a son of Old Chief Smoke, an Oglala Lakota head chief and one of the last great Shirt Wearers, a highly prestigious Lakota warrior society.  He was a signatory to the Fort Laramie Treaty of 1868, along with his brothers Chief Red Cloud and Chief Blue Horse.  A month or so after the Treaty, American Horse was chosen a ""Ogle Tanka Un"" (Shirt Wearer, or war leader) along with Crazy Horse, Young-Man-Afraid-of-His-Horses and Man That Owns a Sword.  On September 9, 1876, American Horse was mortally wounded in the Battle of Slim Buttes fighting to protect his family and defending against the white invasion of the "“Paha Sapa“" Black Hills.

Supporting paragraphs: John Wallace Crawford American Horse (elder)
Answer: American Horse (Oglala Lakota: "Wašíčuŋ Tȟašúŋke" in Standard Lakota Orthography) (a/k/a "American Horse the Elder") (1830–September 9, 1876) was an Oglala Lakota warrior chief renowned for Spartan courage and honor.