A point to consider: As far as I am aware, people of African descent were always allowed to join the Church, all the way back to Joseph Smith times. However, the males could not hold the priesthood.
Another point to consider: If you look at history as a whole, blacks are far from being singled out for not being allowed to hold the priesthood. As I understand it, in ancient Israel, only the Levites held the priesthood...other Israelites of other tribes could not hold the priesthood. And as we near the time of Christ, certainly Gentiles (non-Israelites) were not allowed to have the priesthood. We see God widening the privileges of the priesthood beginning with the gospel being sent to the Gentiles in the time of Peter and Paul. Here in the last days we have seen another progression in expanding the privileges of the priesthood to every worthy male in the world, if they desire to have it and take appropriate steps.
