In 1830, the time this revelation was given, Lamanites were living in Missouri:
Doctrine and Covenants 28:
9 And now, behold, I say unto you that it is not revealed, and no man knoweth where the city Zion shall be built, but it shall be given hereafter. Behold, I say unto you that it shall be on the borders by the Lamanites.
From verse 9 we learn that the location or where the city of Zion shall be build is in an area where there are American Indians or Lamanites. In Section 57, we learn that this is in the state of Missouri and more specifically in Independence, Missouri.
Doctrine and Covenants 57:
1 Hearken, O ye elders of my church, saith the Lord your God, who have assembled yourselves together, according to my commandments, in this land, which is the land of Missouri, which is the land which I have appointed and consecrated for the gathering of the saints.
2 Wherefore, this is the land of promise, and the place for the city of Zion.
3 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.