The Book of Mormon, like other religious books, has its origins myths. An integral part of their story is that god punished the bad tribe (the Lamanites) by giving them dark skin while the favored ones (the Nephites) are given light skin. Brian Keith Dalton (aka Mr Deity) is a former Mormon and he explains how this racism is embedded in the Book of Mormon as an integral part of its theology.
Racism of course runs through religions like capillaries in the body. How could it not when you have to distinguish between the select and the damned? Nowadays religious usually find ways to explain away this awful past by ‘reinterpreting’ those inconvenient passages.
In the Mormon case, it turns out to be particularly hard to do. In this video he explains why it is that to eliminate it would be to undermine the entire Book of Mormon.