linguistic:translation, structural:reformatting, quality:corruption
Great Sioux War of 1876

Sitting Bull's band of Hunkpapa continued to attack migrating parties and forts in the late 1860s. In 1871, the Northern Pacific Railway conducted a survey for a route across the northern plains directly through Hunkpapa lands, it encountered stiff Lakota resistance. The same railway people returned the following year accompanied by federal troops. Sitting Bull and the Hunkpapa attacked the survey party, which was forced to turn back. In 1873, the military accompaniment for the surveyors was increased again, but Sitting Bull's forces resisted the survey "most vigorously." The Panic of 1873 forced the Northern Pacific Railway's backers, such as Jay Cooke, into bankruptcy, which halted construction of the railroad through Lakota, Dakota, and Nakota territory.

After the 1848 discovery of gold in the Sierra Nevada and dramatic gains in new wealth from it, other men became interested in the potential for gold mining in the Black Hills.

In 1874, Lt. Col. George Armstrong Custer led a military expedition from Fort Abraham Lincoln near Bismarck to explore the Black Hills for gold and to determine a suitable location for a military fort in the Hills. Custer's announcement of gold in the Black Hills triggered the Black Hills Gold Rush. Tensions increased between the Lakota and European Americans seeking to move into the Black Hills.

Although Sitting Bull did not attack Custer's expedition in 1874, the U.S. government was increasingly pressured by citizens to open the Black Hills to mining and settlement. Failing in an attempt to negotiate a purchase or lease of the Hills, the government in Washington had to find a way around the promise to protect the Sioux in their land, as specified in the 1868 Treaty of Fort Laramie. It was alarmed at reports of Sioux depredations, some of which were encouraged by Sitting Bull.

In November 1875, President Ulysses S. Grant ordered all Sioux bands outside the Great Sioux Reservation to move onto the reservation, knowing that not all would likely comply. As of February 1, 1876, the Interior Department certified as hostile those bands who continued to live off the reservation. This certification allowed the military to pursue Sitting Bull and other Lakota bands as "hostiles".

Based on tribal oral histories, historian Margot Liberty theorizes that many Lakota bands allied with the Cheyenne during the Plains Wars because they thought the other nation was under attack by the U.S. Given this connection, she suggests the major war should have been called "The Great Cheyenne War". Since 1860, the Northern Cheyenne had led several battles among the Plains Indians. Before 1876, the U.S. Army had destroyed seven Cheyenne camps, more than those of any other nation.

Other historians, such as Robert M. Utley and Jerome Greene, also use Lakota oral testimony, but they have concluded that the Lakota coalition, of which Sitting Bull was the ostensible head, was the primary target of the federal government's pacification campaign.

During the period 1868–1876, Sitting Bull developed into one of the most important Native American political leaders. After the Treaty of Fort Laramie (1868) and the creation of the Great Sioux Reservation, many traditional Sioux warriors, such as Red Cloud of the Oglala and Spotted Tail of the Brulé, moved to reside permanently on the reservations. They were largely dependent for subsistence on the U.S. Indian agencies. Many other chiefs, including members of Sitting Bull's Hunkpapa band such as Gall, at times, lived temporarily at the agencies. They needed the supplies at a time when white encroachment and the depletion of buffalo herds reduced their resources and challenged Native American independence.

In 1875, the Northern Cheyenne, Hunkpapa, Oglala, Sans Arc, and Minneconjou camped together for a Sun Dance, with both the Cheyenne medicine man White Bull or Ice and Sitting Bull in association. This ceremonial alliance preceded their fighting together in 1876. Sitting Bull had a major revelation.

At the climactic moment, "Sitting Bull intoned, 'The Great Spirit has given our enemies to us. We are to destroy them. We do not know who they are. They may be soldiers.' Ice too observed, 'No one then knew who the enemy were – of what tribe.'...They were soon to find out."

Sitting Bull's refusal to adopt any dependence on the U.S. government meant that at times he and his small band of warriors lived isolated on the Plains. When Native Americans were threatened by the United States, numerous members from various Sioux bands and other tribes, such as the Northern Cheyenne, came to Sitting Bull's camp. His reputation for "strong medicine" developed as he continued to evade the European Americans.

After the ultimatum on January 1, 1876, when the U.S. Army began to track down as hostiles those Sioux and others living off the reservation, Native Americans gathered at Sitting Bull's camp. He took an active role in encouraging this "unity camp". He sent scouts to the reservations to recruit warriors and told the Hunkpapa to share supplies with those Native Americans who joined them. An example of his generosity was Sitting Bull's provision for Wooden Leg 's Northern Cheyenne tribe. They had been impoverished by Captain Reynolds' March 17, 1876 attack and fled to Sitting Bull's camp for safety.

Over the course of the first half of 1876, Sitting Bull's camp continually expanded as natives joined him for safety in numbers. His leadership had attracted warriors and families, creating an extensive village estimated at more than 10,000 people. Lt. Col. Custer came across this large camp on June 25, 1876. Sitting Bull did not take a direct military role in the ensuing battle; instead, he acted as a spiritual leader. A week prior to the attack, he had performed the Sun Dance, in which he fasted and sacrificed over 100 pieces of flesh from his arms.