Mormons were actually driven from the United States. At the time they settled Utah, it was part of Mexico. It became a United States territory after the Mexican-American War and was later admitted. Point being, the constitutional republic turned a blind eye toward persecution against Mormons and to survive they had to leave the country and eventually form their own state. Even then, they were threatened by the United States Army. It took decades for the Mormons to be treated as first-class citizens. The United States is a great country, but it has its share of black marks in its history. The treatment of the early Mormons is one of them.