Today is an anniversary few people outside the LDS church are aware of.
On October 27, 1838, Governor Lilburn W. Boggs of Missouri issued an Extermination Order, declaring that "the Mormons must be treated as enemies, and must be exterminated or driven from the State if necessary for the public peace...." Most Missouri citizens backed the order (although some did question or denounce it). The Mormons were, in the simplest of terms, "unwanted."
On October 30, with the Extermination Order as justification, a band of the Missouri Militia launched an attack on a small Mormon settlement at Haun's Mill, killing 17 Mormons, including a 10-year-old boy who was shot in the head as he cowered under the bellows of the blacksmith shop, and a 78-year-old man who was shot after he had surrendered his musket.
For a rare and recently unearthed first-person account, see The Reminiscence of Willard Gilbert Smith.
Several years ago, I spoke with a Latter-Day Saints historian, who told me that survivors of the Massacre sued the state of Missouri over the deaths of their loved ones, taking their case all the way to the Supreme Court. The Court, he said, backed the state on the grounds that the killings were perfectly legal.
Meanwhile, the Extermination Order remained on the books in Missouri until recinded by executive order of Governor Christopher S. Bond on June 25, 1976. So until 1976, it was perfectly legal to kill a Mormon in Missouri. Did that make it right?
According to the prochoicers who argue that since abortion is legal, it's also moral, the answer must be yes.