1) Mormons believe that they have been given America as an everlasting inheritance.
We live in a day when the children of Israel are again to be gathered after their long dispersion. We have heard something of the return of the Jews, the tribe of Judah, to the land of their inheritance, even Palestine; but we are not of that tribe but of the tribe of Joseph, "that bright and glorious morning star," and particularly through Ephraim, his son, and are now being gathered on this the land of Joseph, given to him and his seed as an everlasting inheritance--a land choice above all other lands, the land of liberty, even the land of America. General Conference Report, April 1932, Elder Rulon S. Wells.
2) Mormons believe that Joseph Smith will rule the Western Hemisphere eternally.
We have lived to see this partly fulfilled. There are to be two great capitals. One Jerusalem of old and the other the City of Zion, or New Jerusalem. The latter is to be on this continent. The one will be the Lord's headquarters for the people of Judah and Israel his companions the other for Joseph and his companions on the Western Hemisphere, which was given to Joseph and his seed after him as an everlasting inheritance. Church History and Modern Revelation, Joseph Fielding Smith, Salt Lake City, 1946.
3) Mormons in 1831 were falsely promised land just west of Independence, Missouri.
Wherefore, this is the land of promise, and the place for the city of Zion. And thus saith the Lord your God, if you will receive wisdom here is wisdom. Behold, the place which is now called Independence is the center place; and a spot for the temple is lying westward, upon a lot which is not far from the courthouse. Wherefore, it is wisdom that the land should be purchased by the saints, and also every tract lying westward, even unto the line running directly between Jew and Gentile; And also every tract bordering by the prairies, inasmuch as my disciples are enabled to buy lands. Behold, this is wisdom, that they may obtain it for an everlasting inheritance. Doctrines and Covenants, Section 57, verses 2-5.
4) Mormons now believe that they have a right to the land of Independence, Missouri.
Inasmuch as the location for the New Jerusalem, or the city of Zion, has been identified as Independence, Jackson County, Missouri (D&C 57:1-3), it would seem that the rightful heirs of this land are those members of the Church ("remnants of Jacob") who are called to possess this land of inheritance and build the city of Zion and its promised temple. This "remnant" would not be restricted to only those who are descendants of the people whom Jesus visited in this "land of promise," for the promise was to all of Joseph's posterity. Doctrine and Covenants Encyclopedia, Salt Lake City, Utah, 1996.
Note: True Christians have an eternal inheritance in heaven through faith in Jesus Christ.
Matthew 6:19-20 "Do not lay up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal; but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal."
1 Peter 1:3-5 Blessed be the God and Father of our Lord Jesus Christ, who according to His abundant mercy has begotten us again to a living hope through the resurrection of Jesus Christ from the dead, to an inheritance incorruptible and undefiled and that does not fade away, reserved in heaven for you, who are kept by the power of God through faith for salvation ready to be revealed in the last time.