Genesis flood

Trace mankind down to after the flood, and then another curse is pronounced upon the same race ‑ that they should be the "servant of servants;" and they will be, until that curse is removed; and the Abolitionists cannot help it, nor in the least alter that decree.

Now this king of Egypt was a descendant from the loins of Ham, and was a partaker of the blood of the Canaanites by birth. From this descent sprang all the Egyptians, and thus the blood of the Canaanites was preserved in the land. ... Now, Pharaoh being of that lineage by which he could not have the right of Priesthood, notwithstanding the Pharaohs would fain claim it from Noah, through Ham, therefore my father was led away by their idolatry.

And after the flood we are told that the curse that had been pronounced upon Cain was continued through Ham's wife, as he had married a wife of that seed. And why did it pass through the flood? because it was necessary that the devil should have a representation upon the earth as well as God;...

Ham, through Egyptus, continued the curse which was placed upon the seed of Cain. Because of that curse this dark race was separated and isolated from all the rest of Adam's posterity before the flood, and since that time the same condition has continued, and they have been 'despised among all people.' This doctrine did not originate with President Brigham Young but was taught by the Prophet Joseph Smith .... we all know it is due to his teachings that the negro today is barred from the Priesthood.

Noah's son Ham married Egyptus, a descendant of Cain, thus preserving the Negro lineage through the flood.