Answer by taking a quote from the following article:

Sitting Bull was born on land later included in the Dakota Territory. In 2007, Sitting Bull's great-grandson asserted from family oral tradition that Sitting Bull was born along the Yellowstone River, south of present-day Miles City, Montana. He was named Jumping Badger at birth, and nicknamed Hunkesi, or "Slow," said to describe his careful and unhurried nature. When the boy was fourteen years old he accompanied a group of Lakota warriors (which included his father and his uncle Four Horns) in a raiding party to take horses from a camp of Crow warriors.

From 1866 to 1868, Red Cloud as a leader of the Oglala Lakota fought against US forces, attacking their forts in an effort to keep control of the Powder River Country of Montana. In support of him, Sitting Bull led numerous war parties against Fort Berthold, Fort Stevenson, and Fort Buford and their environs from 1865 through 1868. Sitting Bull also made guerrilla attacks on emigrant parties and smaller forts throughout the upper Missouri River region.  By early 1868, the U.S. government desired a peaceful settlement to Red Cloud's War. It agreed to Red Cloud's demands that the US abandon forts Phil Kearny and C.F. Smith. Gall of the Hunkpapa (among other representatives of the Hunkpapa, Blackfeet, and Yankton Dakota) signed a form of the Treaty of Fort Laramie on July 2, 1868 at Fort Rice (near Bismarck, North Dakota). Sitting Bull did not agree to the treaty. He told the Jesuit missionary, Pierre Jean De Smet, who sought him out on behalf of the government: "I wish all to know that I do not propose to sell any part of my country." He continued his hit-and-run attacks on forts in the upper Missouri area throughout the late 1860s and early 1870s.  The events of 1866-1868 mark a historically debated period of Sitting Bull's life. According to historian Stanley Vestal, who conducted interviews with surviving Hunkpapa in 1930, Sitting Bull was made "Supreme Chief of the whole Sioux Nation" at this time. Later historians and ethnologists have refuted this concept of authority, as the Lakota society was highly decentralized. Lakota bands and their elders made individual decisions, including whether to wage war.

Was there a peaceful end to it?
By early 1868, the U.S. government desired a peaceful settlement to Red Cloud's War.