On October 27, 1838, Missouri’s then-governor, Lilburn Boggs, signed Missouri Executive Order 44, better known as the Mormon Extermination Order.
The executive order demanded that all Mormons leave the state of Missouri, or face extermination. It followed a clash between a group of Mormons and state militia, during a period of conflict that came to be known as the Mormon War, sparked by Mormon prosperity and growth, and suspicion of their beliefs and customs.
Ultimately, 15,000 Muslims fled their homes during the cold winter, heading to Illinois. Although some others who remained in the state were killed, it has been debated whether the Executive Order was a direct cause for the violence, as militia troops may not have been aware of its existence.
The order was not tested in the courts, but nor was it rescinded until over a century later in 1976, by then-Governor Kit Bond.