It seems pretty clear that the “Negroes” talked about by Mormon leaders are mostly descendants of West Africans. It’s true that most African-Americans have ancestors who came from West Africa.
Christianity has traditionally taught that West Africans are descendants of Ham. Baptist, Methodists, as well as Mormons have taught this, and many still teach this. Southern Baptists often used this teaching to justify enslaving West Africans, since Noah cursed Canaan/Ham.
There’s another idea, which argues that Ham and Cain are connected, via Ham marrying Egyptus, a female descendant of Cain. Thus, Ham’s sons (and daughters) are also Cainites. And since Cain himself was cursed by God Himself, that makes Ham’s descendants “doubly cursed”, if you will.
Now, in the Bible, it’s clear that Cain is cursed, and that Canaan/Ham is cursed.
But, to then say that the curse put upon Cain and his descendants, or upon Canaan/Ham and their descendants, is also placed upon West Africans, is to make a non-biblical statement, not stated in the Bible.
In the LDS scriptures, you can find texs that talk about the Ham and Cain curses. That’s not debated.
What is debated, by me as well as by many Mormons, is whether LDS scriptures goes further and states that West Africans are descendants of Ham and Cain. The LDS scriptures say no such thing.
However, many Mormons have indeed believed and taught that Ham and Cain are (1) ancestors of West Africans; AND (2) that the curse on Ham and Cain is still applicable to West Africans. This Mormon belief, many Mormons say, was a result of Mormons accepting uncritically the wider Christian belief of a genetic connection between Ham (and Cain) and West Africans. But this wider Christian belief is also non-scriptural.
So, both Protestants (and Catholics), as well as Mormons of the 19th century made the mistake of genetically connecting Ham (and Cain) with West Africans.
The LDS scriptures talk about a priesthood ban, but a ban against the descendants of Ham/Cain, NOT a ban against specifically Africans, or West Africans.
So, my simple point, is that the LDS African priesthood ban is a result of a multi-step process: (1) the LDS scriptures, including the Bible, talk about curses being applied to Cain and Ham; the LDS texts also state the existence of a Cain/Ham priesthood ban; (2) the non-scriptural, and non-biblical, assumption that West Africans are the descendants of Cain and Ham is then made, by both Protestants (and Catholics) and Mormons, leading to a justification of slavery on the part of many white Protestants; and (3) in the LDS culture, the Cain/Ham priesthood ban is then applied (unscripturally) to West Africans.
Joseph Smith, though, did ordain African-Americans to the priesthood, so obviously J. Smith did not take step 3, even if he may have believed in step 2 and step 1.
Brigham Young brought in step 3.
In 1978, step 3 was rejected by the LDS – and LDS could do this, because step 3 is not supported by LDS scripture.