With the Missouri extermination order Mormons became the only religious group to have a state of the United States legalize the extermination of their religion . This was after a speech given by Sideny Rigdon called the July 4th Oration which while meant to state that Mormons would defend their lives and property was taken as inflammatory . Their forcible expulsion from the state caused the death of over a hundred due to exposure , starvation , and resulting illnesses . The Mormons suffered through tarring and feathering , their lands and possessions being repeatedly taken from them , mob attacks , false imprisonments , and the US sending an army to Utah to deal with the " Mormon problem " in the Utah War which resulted in the Mormons massacring settlers at the Mountain Meadows Massacre . A government militia slaughtered Mormons in what is now known as the Haun 's Mill massacre . The founder of the church , Joseph Smith , was killed in Carthage , Illinois by a mob of about 200 men , almost all of whom were members of the Illinois state militia including some members of the militia who were assigned to guard him
Haun 's Mill massacre
Haun's Mill massacre
Persecution