Why did the mormon faith come under attack while they were settled in nauvoo, illinois? why did the mormons eventually leave?

The correct answer to this open question is the following.

The Mormons were forced to leave Mississippi by the order of the governor. They moved to Quincy, Illinois, in 1889. Joseph Smith ordered the works to make the Noouvo peninsula inhabitable and Mormons established there. But this new place attracted undesirable people such as thieves, and neighbors started to feel uncomfortable. Some people formed the Anti-Mormon Party to remove the Mormons from that land. The polygamy that Mormons practiced also was not accepted by many people in the region, so the confrontation started. By 1884,  the newspaper that revealed the Mormon's polygamy was burned and people started to get weapons to fight each other. Joseph Smith declared martial law. That is when Illinois governor Thomas Ford sent the police to the place. Smith and some of his people surrender and were put on jail but was killed by militiamen. By mid-1845, militiamen pressed the Mormons under the leadership of Brigham Young, and they had to leave Nauvoo and the state.

a big wall across the mexican border so no drugs, terrorist, or illegal immigrants can come through : )