The phrase “the Lord God will raise up a mighty nation among the Gentiles” (1 Nephi 22:7) refers to the United States of America in 1776. The First Amendment to the Constitution of the United States included a proclamation of freedom of religion. These amendments were ratified on December 15, 1791. The Constitution of the United States was where freedom of religion first took root in the modern world.
In 1 Nephi 22:8, Nephi referred to “a marvelous work among the Gentiles” in the latter days. This great work includes the Restoration of the gospel of Jesus Christ and the priesthood keys necessary to bring the covenants of God to “all the kindreds of the earth” (verse 9).
The events in verse 7 had to precede those in verse 8. The world was typically full of countries with forced state religions. For the gospel to be restored, it required a country that both legally professed and practiced freedom of religion. Joseph Smith was born in December 1805, just 14 years after the ratification of the amendments to the Constitution.