Dakota Territory was established by the United States government (this initially included North Dakota, South Dakota, and parts of Montana and Wyoming). Settlement of the area, mostly by people from the eastern United States as well as western and northern Europe, increased rapidly, especially after the completion of an eastern railway link to Yankton in 1873. In 1874, gold was discovered in the Black Hills during a military expedition led by George A. Custer and miners and explorers began illegally entering land promised to the Lakota. Custer's expedition took place despite the fact that the Sioux had been granted the entire western half of present-day South Dakota (West River) in 1868 by the Treaty of Laramie as part of the Great Sioux Reservation. The Sioux declined to grant mining rights or land in the Black Hills, and war broke out after the U.S. failed to stop white miners and settlers from entering the region. Eventually the U.S. won and broke up the Great Sioux Reservation into five reservations, settling the Lakota there. In 1980 the Supreme Court and Congress ordered compensation but the Lakota still refuse to accept it, insisting on return of their land. A growing population in the Dakota Territory caused political dissatisfaction between northern and southern territory residents, with the southern half being always more populated. Following the territorial capital being moved from Yankton to Bismarck in the northern part, calls for dividing the territory increased. Eventually, in 1887 general election, Dakota Territory residents voted for the division, so it was divided in half and President Benjamin Harrison signed proclamations formally admitting South Dakota and North Dakota to the union on November 2, 1889. Harrison had the papers shuffled to obscure which one was signed first and the order went unrecorded. On December 29, 1890, the Wounded Knee Massacre occurred on the Pine Ridge Indian Reservation. Commonly cited as the last major armed conflict between the United States and the Lakota Sioux Nation, the massacre resulted in the deaths of at least 146 Sioux, many of them women and children. 31 U.S. soldiers were also killed in the conflict. During the 1930s, several economic and climatic conditions combined with disastrous results for South Dakota. A lack of rainfall, extremely high temperatures and inappropriate cultivation techniques produced what was known as the Dust Bowl in South Dakota and several other plains states. Fertile topsoil was blown away in