Flag of Deseret.
Flag of the United States of America.
Joseph Smith, at the last minute, does not destroy the printing press that is going to print an exposé on Smith's polygamy and religious power. Rather than being jailed for his cultural crimes, the Illinois state government expels the self-proclaimed prophet, and is eventually taken in by the Utah territorial government, where many Mormons are now gathering.
Smith, now more powerful than ever, began preaching to his fellow Mormons the idea of a country all their own. Originally, calling the proposed country Zion or Jackson (after the supposed location of the Garden of Eden), Joseph Smith eventually settled on the name Deseret sometime in 1849. The independence movement eventually went radical, with new political parties such as the Mormon People's Party and the Deseret National Party taking part in territorial elections.
As talks of serious Southern succession began during the 1860 election, Deseret secession became even more serious. Even though Joseph Smith was now an elderly man, he still lead the Church of Jesus Christ of Latter-Day Saints and the Deseret Independence movement. After the civil war began, and much of Utah's territorial land was ceded to Nevada, Wyoming and Colorado, the Deseret movement became violent. Rebel Mormons, wanting the liberation of Deseret from United States hands, launched an offensive to capture Salt Lake City in the early hours of March 6, 1863. Because of the city's large Mormon population, the city was captured within the week.
With the Confederates realizing they may have a rebel ally, the Confederate government sent diplomats to negotiate a military treaty to help with the defensive line against the Americans. The Deseret government agreed, as the treaty also allowed for a Confederate troop surplus to be sent to the front lines of the new Utah front.
Utah was liberated by the spring equinox of 1864. By this time, Britain and France had sparked an interest in Utah's newfound lucrative mining industry, like the Confederacy's cotton industry. Because Utah, like Britain and France have outlawed slavery, the two empires can freely associate themselves with the liberated Deseret.
Even with Utah's assistance to the Confederate front lines, the Confederacy falls, however, three months later than in the OTL. However, Deseret has given Britain and France access to its mining industry, and in turn, the two countries have given Deseret military assistance. The United States reluctantly signs a peace treaty in order to avoid a proxy war with the British or French empires. The peace treaty cedes part of Deseret to Wyoming Territory in return for a Status Quo. Joseph is declared interim President of Deseret until the official presidential election on March 6, the anniversary of the start of Deseret liberation.
Nowadays, the Republic of Deseret is a democratic state with a large nuclear program and allied with the United States. United States Union referenda are held every year, and so far, the percentage voting yes has never reached past 35%.