BYU Professor Margaret Blair Young is one of the LDS Church's foremost scholars of the former Priesthood ban, and she wrote a post on By Common Consent last weekend that is a short, powerful, insightful explanation of the genesis of the idea that black people are descendants of Cain and, therefore, "cursed" with black skin. There are lots of other writings that go into much more detail about why our former reading of scriptures has been incorrect, but Margaret's post is an excellent starting point for anyone who doesn't understand how horribly flawed the curse of Cain nonsense really is.
As is generally the case when I write specifically about the ban, this post is in response to recent statements by members who can't let go of the former justifications. I am linking Margaret's post in the hope that someone will read it who has assumed there actually was such a curse - that someone who has believed it will be able to see how misguided and non-historic that justification was.
With that introduction, here is the link:
"An Exception Having Been Made...OR You May Be a Racist If... - Margaret Blair Young (By Common Consent)