Next came the struggle of the Western Sioux and Northern Cheyennes in defence of their homes. The building of the Northern Pacific and the Union Pacific transcontinental railroads had necessitated the making of new treaties with these people. Scarcely was the agreement completed by which they ceded a right of way in return for assurances of permanent and absolute possession of other territory, including the Black Hills and Bighorn Mountains, when gold was discovered in these regions. This fact created great excitement and a general determination to dispossess the Sioux of the country just guaranteed to them, which no white man was to enter without the consent of three fourths of the adult men of the tribe. Public excitement was intense, and the Government found itself unable to clear the country of intruders and to protect the rights of the Sioux. It was reported that there were no less than fifteen thousand men in the Black Hills district placer-mining and prospecting for the yellow metal. The authority of the United States was defied almost openly by the frontier press and people. Then the Indians took matters into their own hands, carried on a guerilla warfare against immigrants, and harassed the forts until the army was forced to enter upon a campaign against them. In 1868 another treaty was made, but the great chief, Red Cloud, would not sign it until he saw forts C. F. Smith and Phil Kearney abandoned. Here is probably the only instance in American history in which a single Indian chief was able to enforce his demands and make a great government back down. At that time it would have cost immense sums of money and many lives to conquer him, and would have retarded the development of the West by many years. It is a fact that Sitting Bull was thoroughly opposed to yielding any more territory. No doubt he foresaw the inevitable result. He had taken up the cause of the Eastern Sioux in Minnesota and fought Sibley and Sully in 1862. He had supported Red Cloud in his protests against the establishment of the Bozeman trail, and against the new forts, although thus far these aggressions had not affected him directly. But when surveyors began work on the Northern Pacific, they entered his particular domain, and it was time for him to fight in its defence. Unfortunately for him, the other bands of Sioux whom he had helped in their time of need were now all settled upon reservations, so that he had not much support except from Crazy Horse's band, and the so-called hostiles or renegades of the Western bands. Hostilities began in 1872, culminating in 1876 with the famous "Custer fight," which practically ended the struggle, for after annihilating Custer's command the Indians fled into British America. Four years later Sitting Bull was induced to come in and settle down upon the Sioux reservation.