Take a moment to think about history of US statehood. The Mormons, chased off Eastern settlements for their polygamy, settled most of the mountain West, declared governance, then watched big mining operations all around them get cut off from their territory and turned into full-fledged states, while they were not admitted to the union for decades.
It was a time of shared culture that is unrecognizable from where we stand today, and they absolutely didn't want to give statehood to polygamists...
I'm seeing no mention of Mormons breaking laws, the only mentions of law breaking references other people breaking laws to persecute Mormons. The governor of Missouri's declares that they are to be expelled or exterminated (!!!), the mobs attacked them and killed them, no mention anywhere in your link of Mormons breaking any laws.
Note that I do not take the position that Mormons broke no laws, I'd just like to know what laws they broke, and particularly what federal laws they broke, since my reply is to the claim that they broke American laws and not of some specific state.