Utah did not attract much attention from early European explorers. The Spanish explored Arizona in 1540 and perhaps saw some of Utah, but the first definite exploration was in 1776, when a pair of Franciscan friars led an expedition into the Utah area. No settlements followed, however. The first Americans to visit were probably fur traders around 1811. The American scout Jim Bridger was the first white man known to have seen the Great Salt Lake during the winter of 1824-1825. Since the water tasted salty, he believed he had reached the ocean.
The Mormons were the first permanent settlers. First organized in New York, the Mormons were persecuted there, and in several more locations before they finally decided to migrate to a place where they could live in peace. They set out from Illinois in 1846 and reached the Great Salt Lake region in 1847. It was part of Mexico at the time, but soon afterwards, the treaty ending the Mexican War gave the area to the United States. In 1849, the Mormons set up the State of Deseret. As part of the Compromise of 1850, the United States established the Utah territory, which included present-day Utah and land to the west.
The Mormon practice of polygamy, although not widespread, caused opposition in Congress to Utah statehood. President Buchanan appointed a new territorial governor to replace the Mormon leader Brigham Young in 1856 and sent federal troops to guarantee control. The troops remained until the outbreak of the Civil War.
Utah's isolation was reduced with the arrival of the Pony Express, the Telegraph, and the transcontinental railroad. Congress approved Utah's current boundaries in 1868 and finally, in 1895, after passage of a new state constitution that prohibited polygamy, Utah was admitted as the 45th state of the Union.