Meanwhile President Buchanan responded to rising criticism by publicly appointing two commissioners, Lazarus Powell and Ben McCulloch, to carry an amnesty proclamation to the Mormons. Upon reaching Utah in early June, they found Young and his colleagues willing to accept forgiveness for past offenses in exchange for accepting Cumming and the establishment of an army garrison in the territory. When Johnston's army marched through a deserted Salt Lake City on 26 June 1858 and then went on to build Camp Floyd forty miles to the southwest, the Utah War was over.

As governor, Cumming soon became more popular with the Mormons than with the military forces that had remained until the outbreak of the Civil War. With the nearby civilian town of Fairfield, Camp Floyd represented the first sizable non-Mormon resident population in Utah, and it ended forever the Mormon dream of a Zion geographically separate from the world of unbelievers. As for the Mormon community in Utah, the exertions and expenditures associated with the Nauvoo Legion efforts and the Move South taxed both capital and morale. The war terminated the Mormon outpost settlements in present day California, Nevada, Wyoming and Idaho, interrupted and weakened the missionary effort in Europe, and dissipated much of the enthusiasm and discipline that had earlier been generated by the Reformation of 1856. As a demonstration of sacrificial zeal, the Move South won some sympathy, but it did not improve the prospects for Utah statehood or increase toleration of Mormon differences from mainstream American ideas and institutions.

See: Norman F. Furniss, The Mormon Conflict, 1850-1859 (1960, 1977); Richard D. Poll, Quixotic Mediator: Thomas L. Kane and the Utah War (1985).