Joseph Smith reveals "it is not right that any man should be in bondage one to another."
Revelation Book 1, 188, The Joseph Smith Papers website, accessed August 11, 2021
. . .according to the law and constitution of the people which I have suffered to be established; and should be maintained for the rights and protection of all flesh, according to Just and holy principals, that every man may act in doctrine and principal partaining to futurity, according to the moral agency of which I have given unto them, that every man may be accountable for his own sins in the day of Judgment. Therefore, it is not right that any man should be in bondage one to another. And for this purpose have I stablished the constitution of this land by the hands of wise men, whom I raised up unto this very purpose, and redeemed the land by the shedding of blood.