Here is just some of what the Mormon Elders state on the subject:
There is a reason why one man is born black and with the other disadvantages, while another is born white with great advantages. The reason is that we once had an estate before we came here, and were obedient, more or less, to the laws that were given us there. Those who were faithful in all things there received greater blessings here, and those who were not faithful recieved less. - Joseph Fielding Smith - 10th LDS President
In 1966, Bruce McConkie(ordained an apostle in 1972) his book Mormon Doctrine said"The negroes are not equal with other races where the receipt of certain spiritual blessings are concern . . .but this inequity is not of man's orgin. It is the Lord's doing."
The Negro is an unfortunate man. He has been given a black skin. But that is as nothin compared with the great handicap that he is not permitted to receive the Priesthood and the ordinances of the temple, necessary to prepare men and women to enter and enjoy a fullness of glory in the celestial kingdom - George Richards - Mormon Elder