This verse tells us of some called to go on a mission to the Lamanites. This is supposed to be a direct revelation from God, and “Lamanites” means “Native Americans.” The Doctrine and Covenants Student Manual confirms this saying, “By ‘Lamanites’ Joseph Smith had reference to the Indians, and to go out to the ‘borders by the Lamanites’ meant to go to the frontier.”
This was the consensus among the prophets and apostles ... until it wasn’t, in recent decades. Though God was quite clear in the Doctrine and Covenants who the Lamanites were, though the prophets and apostles were unambiguous in teaching that by “Lamanites” the scriptures mean “Native Americans,” the current leaders of the Church do not seem to know who the Lamanites are, even though the Book of Mormon was “Written to the Lamanites” (Book of Mormon Introduction) and the Book of Mormon has many references to how its writings are to be preserved for the Lamanites.
(See also, “Who is Moroni writing to? ”)