Did new Yorkers ever commit genocide on unarmed women and children passing through like the Mormons did at Mountain Meadows? No?
Was the US Army ever sent to destroy New York City like they were sent to eliminate a Godless polygamist cult of murders? No?
Stop.
Right there.
In order to understand what happened in 1858, you need to understand what happened in 18
38.
Back when the LDS faith was headquartered in Missouri, tensions were high between the membership and the locals. A major part of this came from the fact that the church's rapid growth meant that in a few years the church would represent the majority population of the state, thereby allowing the church the opportunity to take control at the ballot box and thereby control the state by fiat. In particular, the locals were concerned that the church - whose members largely opposed slavery - would use their majority to push through abolition.
Outbursts of mob violence had taken place just a few years earlier, during which a printing press used to publish church documents was destroyed in an effort to keep the church from spreading its message. As such, both sides were already on edge. The locals again resorted to mob violence in 1838, this time in an effort to keep Mormons living in Gallatin County from voting during election day. When Mormon reinforcements resulted in the mob being chased away, other mobs sprang up. In short order, Mormon settlements were getting raided left and right. Appeals to the local, state, and federal governments all fell on deaf ears, forcing the Mormons to form militias of their own to protect against the mobs.
This led to the Battle of Crooked River, where one such militia encountered a mob that was resting by said river. What the militia didn't know was that the mob included a state militiaman who had deserted his post to join the fighting. The person in question was killed during the exchange, leading to Governor Boggs receiving false reports that the church was in open rebellion against the state government. In response, Boggs issued the "Extermination Order" requiring that the state militia
kill any Mormon who refused to leave the state.
That's right, folks: we Mormons were on the receiving end of state-sanctioned religious pogroms.
Not long after the order was issued, a group of state militia rode into the Mormon settlement of Haun's Mill and shot the place up. Not satisfied with just killing all of the adult men in town, the militia shot one boy as he was trying to run away and
executed a second boy in front of his mother.
Fast forward 20 years.
A corrupt federal official was run out of Utah after his servant bushwhacked a Mormon who had been a vocal critic of the official. In retaliation, he wrote a false report back stating that Utah was in open rebellion. For reasons that have never been explained, President Buchanan took him at face value and ordered 1,000+ soldiers sent into the territory. In his haste, Buchanan never issued notice of intent. Given what had happened in Missouri and Illinois, when the church found out about the incoming army a panic set in across the territory.
As part of the panic, people across the territory began to hoard supplies. This left the Franchers - who had not taken enough supplies for the full trip to California - trapped without enough goods to get them the rest of the way. The Franchers traded some of their cattle to the local Paiute band in exchange for food, but disease quickly tore through the Paiutes shortly thereafter, leading the Paiutes to believe that the Franchers had deliberately poisoned them. The local militia leader and a local religious leader were already looking for an excuse to justify whacking the Franchers because they came from Missouri and Arkansas (popular church leader Parley Pratt had just been lynched in Arkansas after winning a rather sensational court case). When they found out that there were now dead Paiutes, they reached out to the band and struck an unholy deal.
A local political leader had sent word to Brigham Young informing him that the Paiutes believed the Franchers tried to poison them. Young responded by issuing an order for the local militia to stand down and let the Paiutes do as they pleased. However, the order arrived a day too late; by then it had already happened. The local leadership officially put out a story saying that the Paiutes had descended upon the Franchers, leaving only some young children alive. Young believed this story, and was so confident that the militia was innocent he offered to use his position as head of the church to compel people to testify when the government first launched an investigation in 1859. This investigation was abruptly halted, and would not resume for another 20 years.
In that sense, whatever you were told about what happened was likely just so much bupkis.