History of the Church, Joseph Smith 1:315
And now I am prepared to say by the authority of Jesus Christ, that not many years shall pass away before the United States shall present such a scene of bloodshed as has not a parallel in the history of our nation; pestilence, hail, famine, and earthquake will sweep the wicked of this generation from off the face of the land, to open and prepare the way for the return of the lost tribes of Israel from the north country.
Journal of Discourses, Joseph Smith 20:41
Were we surprised when the last terrible war took place here in the United States? No; good Latter-day Saints were not, for they had been told about it. Joseph Smith had told them where it would start, that it should be a terrible time of bloodshed and that it should start in South Carolina. But I tell you today the end is not yet. You will see worse things than that, for God will lay his hand upon this nation, and they will feel it more terribly than ever they have done before; there will be more bloodshed, more ruin, more devastation than ever they have seen before. Write it down! You will see it come to pass; it is only just starting in. And would you feel to rejoice? No; I would feel sorry. I knew very well myself when this last war was commencing, and could have wept and did weep, over this nation; but there is yet to come a sound of war, trouble and distress, in which brother will be arrayed against brother, father against son, son against father, a scene of desolation and destruction that will permeate our land until it will be a vexation to hear the report thereof.
Journal of Discourses, Orson Pratt 20:18
And the Lord also made a similar decree, recorded, too, in the same book, in regard to the present great populous nation called the people of the United States. They must perish, unless they repent. They will be wasted away, and the fullness of the wrath of Almighty God will be poured out upon them, unless they repent. Their cities will be left desolate. A time is coming when the great and populous city of New York–the greatest city of the American Republic, will be left without inhabitants. The houses will stand, some of them, not all. They will stand there, but unoccupied, no people to inherit them. It will be the same in regard to numerous other cities, or, in the words of the Lord, “I will throw down all their strongholds, and I will execute vengeance and fury upon them, even as upon the heathen, such as they have not heard.” It will all be fulfilled. But there will be a remnant who will be spared. It will be those who repent of their sins; it will be those who believe in the Lord Jesus Christ, and are willing to obey his commandments, willing to hearken to his voice, willing to be baptized for the remission of their sins, willing to be born of the spirit, or receive the Holy Ghost by the laying on of hands, willing to walk uprightly and honestly with all men, and justly one with another.
Journal of Discourses, Orson Pratt 20:18
But what about the American nation. That war that destroyed the lives of some fifteen or sixteen hundred thousand people was nothing, compared to that which will eventually devastate that country. The time is not very far distant in the future, when the Lord God will lay his hand heavily upon that nation. … It will be a war of neighborhood against neighborhood, city against city, town against town, county against county, state against state, and they will go forth destroying and being destroyed and manufacturing will, in a great measure, cease, for a time, among the American nation. Why? Because in these terrible wars, they will not be privileged to manufacture, there will be too much bloodshed–too much mobocracy–too much going forth in bands and destroying and pillaging the land to suffer people to pursue any local vocation with any degree of safety. What will become of millions of the farmers upon that land? They will leave their farms and they will remain uncultivated, and they will flee before the ravaging armies from place to place; and thus will they go forth burning and pillaging the whole country; and that great and powerful nation, now consisting of some forty millions of people, will be wasted away, unless they repent.
Scriptural Teachings of the Prophet Joseph Smith :161
I saw men hunting the lives of their own sons, and brother murdering brother, women killing their own daughters, and daughters seeking the lives of their mothers. I saw armies arrayed against armies. I saw blood, desolation, fires. The Son of Man has said that the mother shall be against the daughter, and the daughter against the mother. These things are at our doors. They will follow the Saints of God from city to city. Satan will rage, and the spirit of the devil is now enraged. I know not how soon these things will take place; but with a view of them, shall I cry peace? No; I will lift up my voice and testify of them. How long you will have good crops, and the famine be kept off, I do not know; when the fig tree leaves, know then that the summer is nigh at hand.