originally posted at Juvenile Instructor
Doctrine and Covenants 84:3-4 instructs the Latter-day Saints concerning the city of Zion, which was to be their "New Jerusalem:"
3 Which city shall be built, beginning at the temple lot, which is appointed by the finger of the Lord, in the western boundaries of the State of Missouri, and dedicated by the hand of Joseph Smith, Jun., and others with whom the Lord was well pleased.
4 Verily this is the word of the Lord, that the city New Jerusalem shall be built by the gathering of the saints, beginning at this place, even the place of the temple, which temple shall be reared in this generation.
When the Mormons were expelled from Jackson County at the end of 1833, they were quite understandably worried about what to do with their property. As they relocated in what would become Nauvoo, Illinois, they were instructed to put their energy and resources into building this new home. In March 1839 Joseph Smith "counseled to sell all the land in Jackson county, and all other lands in the state whatsoever."  Within the next two years, a revelation was given absolving the Saints of their responsibilities by the word of the Lord: ". . . I have accepted the offering of those men who I commanded to build up a city and a house unto my name in Jackson county, Missouri..." They were told that if enemies hindered them from their work, God would "require that work no more." 
It seems fascinating to me that in spite of the rescinding of the requirement to build Zion in Jackson County, leaders of the Church remained dedicated to the idea that the New Jerusalem would be raised in Missouri. Soon after the death of Joseph Smith, Brigham Young, speaking as president of the council of Twelve Apostles, stated in a conference on April 6, 1845:
"And when we get into Jackson county to walk in the courts of that house, we can say we built this temple: for as the Lord lives we will build up Jackson county in this generation." 
This sentiment was perpetuated after the Mormons were established in the Salt Lake Valley. In 1871 Orson Pratt referred to D&C 84 and publicly insisted,
"Here then we see a prediction, and we believe it. Yes! The Latter-day Saints have as firm faith and rely upon this promise as much as they rely upon the promise of forgiveness of sins when they comply with the first principles of the Gospel. We just as much expect that a city will be built, called Zion, in the place and on the land which has been appointed by the Lord our God, and that a temple will be reared on the spot that has been selected, and the corner-stone of which has been laid, in the generation when this revelation was given; we just as much expect this as we expect the sun to rise in the morning and set in the evening; or as much as we expect to see the fulfillment of any of the purposes of the Lord our God, pertaining to the works of his hands. But say the objector, 'thirty nine years have passed away.' What of that? The generation has not passed away; all the people that were living thirty-nine years ago have not passed away; but before they do pass away this will be fulfilled." 
Pratt exhibited full confidence that the D&C's prophecy concerning the Missouri temple being reared "in this generation" would come to pass. But even more, he considered the establishment of Zion in Jackson County as essential to the LDS faith as the forgiveness of sins!
Even after the generation who was alive at the time of Joseph's prophecy began to pass on, the hope was kept alive within the membership of the Church that one day a temple would be raised in Jackson County. Tidbits of information concerning the events of the last days often included references to Missouri. In October Conference of 1930, J. Golden Kimball remarked: "[t]he western boundaries of the State of Missouri will be swept so clean of its inhabitants that as President [Brigham] Young tells us, 'when we return to that place there will not be as much as a yellow dog to wag his tail.'" 
I find little evidence that any of the Mormons were willing to escape their responsibility to build up Zion in Jackson county by applying the revelation given in 1841 that the Lord no longer required it. Instead, in October 1967 we see an interesting occurrence. President David O. McKay announced plans to build a Visitors Center across the street from the Temple Lot in Independence, on part of the original parcel of ground set apart for this purpose. Alvin R. Dyer, though not a member of the Quorum of the Twelve, was made an Apostle on October 5, 1967, with the blessing pronounced on him that he was to be a watchman over the consecrated lands in Missouri.  While serving in this capacity, Dyer wrote a book about the destiny of the Church in Zion, which he titled The refiner's fire: The significance of events transpiring in Missouri. Dyer often spoke and wrote about his goal of reviving Independence and the general Jackson county area in the consciousness of the Church.
While still an Apostle, Spencer W. Kimball became interested in the gathering of American Indians ("Lamanites") into the Church. As his inspiration, he took D&C 52:2 where instructions are given to convene the next conference in Missouri where missionaries to the Indians had gone. In this verse, the Lord consecrates the land to his people, the "remnant of Jacob." Elder Kimball gave his opinion of why the temple in Independence had not been built in a timely manner:
I've known people who have been promised in their patriarchal blessings that they would live to see the temple built and some of them are dying and haven't seen the temple built. Do you know why? In my estimation, the Lord's time table is directed a good deal by us. We speed up the clock or we slow the hands down and we turn them back by our activities or our procrastinations. And do you know why I think people who are actually promised that they would live to see the temple built are dying before the completion of the temple? Because we haven't converted the Indians in large enough numbers; never shall we go to Jackson County until we have converted and brought into this church great numbers of Lamanites. Now you just as well set that down as a basic fact. 
After the Church began to acquire land in the vicinity of Jackson county and following the organization of multiple stakes in Missouri, additional folklore began to develop concerning the return to Zion. In the late 1970's the Church made an effort to counter the myths that were circulating. Graham W. Doxey, former president of the Missouri Independence Mission, warned Church members:
Myth #1: We’re going to walk to Missouri to prepare for the Second Coming. Scripture makes it clear that Missouri has a prophetic role to play in the Second Coming and it seems logical that some people will need to go there to assist in portions of that work. But the scriptures contain no references that spell out in detail how that assistance will be given.
One of the quotations I hear frequently repeated is part of a sermon by Joseph F. Smith in 1882: “When God leads the people back to Jackson County, how will he do it? Let me picture to you how some of us may be gathered and led to Jackson County. I think I see two or three hundred thousand people wending their way across the great plain enduring the nameless hardships of the journey, herding and guarding their cattle by day and by night. … This is one way to look at it. It is certainly a practical view. Some might ask, what will become of the railroads? I fear that the sifting process would be insufficient were we to travel by railroads.” (Journal of Discourses, 24:156–57.)
This is a vivid mental picture, but people frequently remember the picture and forget he said “some of us” and “may be gathered.” We should also keep in mind that he said this is “one way to look at it,” remembering also the perspective of 1882. From our perspective in 1979, it seems even less likely that we would sell our automobiles and herd cattle along our freeway systems. But we simply have no scriptural information about who—if any general Church members—will be called to go back and the means that they might use. The prophets of our day have not found it timely or necessary to speak on the matter. 
Despite these cautions, thousands of members of the Church still have in their minds the romantic picture of walking to Jackson County in the latter days. With the announcement in the October 2008 General Conference of a temple to be built in "the greater Kansas City area," imaginations have again been fired. Where will the Temple be located? Are the last days upon us? Is this the beginning of an effort to bolster the Church's presence in an area of religious significance for the Mormons?
 History of the Church 3:274-75.
 H. Michael Marquardt, The Independence Temple of Zion. This revelation came from the manuscript volume "Book of the Law of the Lord, and was read by John C. Bennett at the April 1841 General Conference.
 Times and Seasons 6 (1 July 1845):956.
 Journal of Discourses, Vol. 14, p. 275.
 J. Golden Kimball, Conference Report, October 1930, p.59.
 H. Michael Marquardt, The Independence Temple of Zion. Dyer was later set apart as a third counselor in the First Presidency (1968). This was one of the very few times when a man who was not a member of the Council of the Twelve served as an Apostle.
 Ibid. From a copy of the December 1963 talk obtained from President Kimball's secretary as quoted in Book of Mormon Student Manual (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 2nd ed., 1981), 427-28. Kimball speaking to the Lamanites [Indians] said: "You must flourish, and you must become a great people so that you can go back to Jackson County with us and we with you, and we will build there the magnificent temple which Orson Pratt said will be the most beautiful building that ever was built or that ever will be built. . . . They must be leaders in their communities, because not too far away there is going to be a great migration to Jackson County, Missouri, and there we are going to build the great temple" (426-27).
 Graham W. Doxey, “Missouri Myths,” Ensign, Apr 1979, 64