The Book of Mormon is a record of ancient scripture written on the American continent and preserved in upstate New York until it was revealed by an angel in the 1800s. The people who kept the record were descendants of several families who immigrated from Jerusalem near the fall of that city. The Book of Mormon does not mention currently existing civilizations, but most Mormons do not currently believe the continent was empty when the people of the Book of Mormon arrived. The book, which was condensed by the last two writers of it, simply doesn’t mention others.
The prophets of the two civilizations that developed from these people prophesied concerning what would someday be the United States of America. In Second Nephi, the prophet Lehi recorded a vision concerning the continent and the future nation. He was told the land was covenanted to his family and to others who would come to it from around the world by the hand of God. He learned that no one would come to the land unless brought by the hand of God.
Lehi was told in the vision that if the people who lived there would keep the commandments, the land would be one of liberty and would never be taken into captivity by another nation.
To read the entire article: Mormon Beliefs
