On paper, the United States was relatively quiescent in the 1870s: the only territorial acquisitions were the Juan de Fuca Islands in the northwest (1872) in settlement of a long-running dispute with Canada, the only new state Colorado (admitted in 1876). But the decade saw the pacification of the frontier reach its turbulent crescendo, with the remaining territories of the ‘Wild West’ strewn with lawless mining and cattle towns, and Indian wars nearing their bloody conclusion. From 1868, most of Southwest Dakota Territory had been set aside as the Great Sioux Reservation, but completion of the trans-continental railroad precipitated rising tides of settlers and prospectors, turning to a flood when an expedition led by Colonel Custer discovered gold in the Black Hills (1874). The Sioux would gain their revenge on Custer, only to be broken by the savage reprisal. Thereafter, apart from Apache guerrilla warfare, the incorporation of the frontier was effectively process, not conquest.
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