Leonard J. Arrington, "Young, Brigham," American National Biography Online, February 2000, http://www.anb.org/articles/08/08-01714.html.
The Utah War ended in 1858 without the loss of life, but friction continued between Colonel Johnston, who distrusted Young and his associates, and the settlers, virtually all of whom were loyal to Young. With the outbreak of the Civil War, the army abandoned the territory, some to fight for the North and some for the South. Young contracted on behalf of the church to erect the hurriedly built transcontinental telegraph within Utah borders and then constructed a church-owned telegraph system to connect each settlement with Salt Lake City and the nation. Not entirely certain of Mormon loyalty to the Union, [President Abraham] Lincoln sent a regiment of California volunteers to Utah. They established Camp Douglas in central Salt Lake City to prevent Indian raids and "watch over the Mormons." Their leader, Patrick Connor, was violently anti-Mormon and used his troops to prospect for minerals in Utah's mountains, hoping to induce a rush of miners to the territory to outnumber the Mormons. Minerals were found, but they could not be economically worked until the completion of the transcontinental railroad in May 1869.