In 1870, just before the advent of the railways, the estimated white population of present North Dakota was not more than five hundred. Pembina County, extending the length of the Red River Valley and to the western population limit, was the only organized county in the State. The Northern Pacific was completed to the Pacific Coast in 1883. Squatters preceded the railroad, settlers followed it, trying to guess future town sites so they could force the company to buy them out at the most profitable price. The Great Northern was the second important railroad to come into the State. By 1882 James J. Hill, the "Empire Builder," had extended a line up the Dakota side of the Red River to Canada. Hill had a vision of a great railroad connecting the Pacific Coast with the Great Lakes, whence produce could be cheaply transported to New York. Construction began in 1880 and the Great Northern was extended westward across northern North Dakota and in 1893 reached the Coast. The railroads linked Dakota with the East and civilization, but to the west was the frontier. Here Sioux warriors were beginning to resent the encroaching whites and the appropriation of their hunting grounds. It was imperative, therefore, that soldiers be kept at Fort Abraham Lincoln. To understand the campaign of 1876 against the Sioux, in which Gen. George A. Custer met his tragic end, it is necessary to go back to the Indian treaty of 1868. The Government by this pact promised to abandon and destroy Forts Reno and Phil Kearney in Wyoming and Fort Smith in Montana. This having been done, the Sioux were guaranteed their freedom in the territory between the North Platte and the Missouri and Yellowstone Rivers. But, when gold was discovered in the Black Hills by a Government reconnaissance expedition under Custer in the summer of 1874, white settlers and prospectors begged for admission to the coveted territory. Military guards at first attempted to keep them out, but when the Indians refused in a treaty council in 1875 to sell or lease land to miners, the Government withdrew the guard and settlers poured in by thousands. [Illustration: RING-BILLED GULLS _Photo by Russell Reid_] [Illustration: PASQUES _Photo by Russell Reid_] [Illustration: FLICKERTAIL _Photo by Russell Reid_] [Illustration: A MODERN INDIAN _Photo by Russell Reid_] [Illustration: SCAFFOLD BURIAL, FORMERLY USED BY SOME INDIAN TRIBES] Government officials were well aware, when the treaty of 1868 was violated, that an Indian war was inevitable; but although the Government had clearly brought the war down on its own head, it sought the appearance of righteousness.