State in the Rocky Mts in the NW part of the country, admitted to the Union in 1890 as the 43rd state. Its name comes from an Indian word for the Comanche tribe and was originally proposed for what became Colorado. Montana and British Columbia are to the N, Wyoming to the E, Utah and Nevada to the S, and Oregon and Washington to the W.
The first documented European Americans in the region were Meriwether Lewis and William Clark on their journey of exploration to the Pacific in 1805. The next visitors were fur traders, and the Canadian David Thompson established the first trading post in 1809. The first American post was started the next year by Andrew Henry near present Rexburg. Competition between Canadians and Americans was so strong that by the 1840s the fur supply was greatly depleted.
In the 1830s and 1840s several American explorers, traders, and missionaries entered the area. These included Benjamin L.E. Bonneville in 1832; Nathaniel Wyeth, who founded Fort Hall near Fort Boise
in 1834; Henry Spaulding, who started a mission in 1836 at Lapwai near present Lewiston; John C. Frémont; and Kit Carson. At this time Idaho was part of the Oregon Country, a region held jointly by the United States and Great Britain. In 1846 the two nations agreed on the line of the 49th parallel as the international boundary; and in 1859, when Oregon became a state, Idaho was made part of Washington Territory.
It was 1860 before a permanent settlement was made, this being a Mormon religious outpost at Franklin. The discovery of gold at different locations in the years 1860 to 1863 brought a rush of prospectors, who left behind them many ghost towns. Nevertheless, the permanent population increased enough so that Idaho became a territory in 1863. The influx of whites angered the numerous Indian tribes of the region, and some of them began attacking the newcomers. Fighting lasted from 1863 to 1878. Most notable was the long flight of Chief Joseph and the Nez Percé Indians who, in a 1,000-mile march during the period 1876–77, tried unsuccessfully to escape the pursuing U.S. forces and reach Canada.
Another mining boom began in 1882 after gold was struck near Coeur D’Alène, followed by discoveries of silver and lead. The late 19th century also saw the development of cattle and sheep ranching and fighting between these two interests. Organized labor activity led to violence and political struggles after Governor Frank R. Steunenberg was assassinated in 1905. He had used troops to put down dissidents. The trial of William Haywood and others accused of being involved in the murder drew national attention but ended in acquittal.
Idaho’s economy benefited from the coming of the railroads in the 1880s and 1890s, irrigation projects in the early 20th century, and hydroelectric power development in the 1950s and 1960s. The state has voted Republican in presidential elections since 1968. Boise is the capital and the largest city; others are Pocatello and Idaho Falls.