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Question: Was Brigham Young a racist?
Question: Was Brigham Young a racist?
Brigham Young made a number of statements which are now considered blatantly racist
Brigham Young made a number of statements which are now considered blatantly racist. 
Why did past prophets make racist statements? God had already revealed to Peter that he should not call anything "common" that God had cleansed (Acts 10:9-16), yet some modern-day prophets thought that blacks were inferior to whites; why is that?
Elder Neil L. Anderson said,
A few question their faith when they find a statement made by a Church leader decades ago that seems incongruent with our doctrine. There is an important principle that governs the doctrine of the Church. The doctrine is taught by all 15 members of the First Presidency and Quorum of the Twelve. It is not hidden in an obscure paragraph of one talk. True principles are taught frequently and by many. Our doctrine is not difficult to find.
The leaders of the Church are honest but imperfect men. Remember the words of Moroni: “Condemn me not because of mine imperfection, neither my father … ; but rather give thanks unto God that he hath made manifest unto you our imperfections, that ye may learn to be more wise than we have been” (Ether 12:6). 
We should be forgiving of past prophets who we today would perceive as being "racists," or otherwise unsophisticated when compared to the present day
We should be forgiving of past prophets who we today would perceive as being "racists," or otherwise unsophisticated when compared to the present day. Lest we judge harshly, we ought to consider that even the Savior himself spoke of "outsiders" using language that we today would consider grossly offensive (Matthew 15:26).
We are warned, however, that we will be judged in the same manner in which we judge others (Matthew 7:2, Mark 4:24). If we condemn those of the past for being imperfect or influenced by their culture, what can we expect for ourselves?
“On the day I arrived, students had seen the segment in which Governor Ross Barnett physically bars James Meredith from registering at Ole Miss. In the ensuing discussion, the teacher asked students why Barnett objected to Meredith’s enrollment. One boy raised his hand and volunteered, ‘Prejudice.’ The teacher nodded and the discussion moved on.
“That simple ‘prejudice’ unsettled me. Four hundred years of racial history reduced to a one-word response? This set me to wondering what would it take before we begin to think historically about such concepts as ‘prejudice,’ racism,’ ‘tolerance,’ fairness,’ and ‘equity.’ At what point do we come to see these abstractions not as transcendent truths soaring above time and place, but as patterns of thought that take root in particular historical moments, develop, grow, and emerge in new forms in successive generations while still bearing traces of their former selves?”
- — Sam Wineburg, Historical Thinking and Other Unnatural Acts (Philadeliphia: temple University Press, 2001), 17.
The perception that past prophets were "just like us" is incorrect
In the Church we spend a lot of time "likening the scriptures unto ourselves," to use Nephi's phrase (1 Nephi 19:23).
This approach has the advantage of making the teachings of the scriptures and early Church leaders apply to us, so they become agents of change in our lives, rather than just artifacts to be studied in a detached way.
The disadvantage of this approach, though, is that it can build the perception that past prophets were "just like us" — having all the same assumptions, traditions, and beliefs. But this is not the case at all. Prophets in all dispensations have been "men of their times," who were raised with certain beliefs and interacted all their lives with others who shared those beliefs.
For example, the Old Testament peoples believed the earth was a flat expanse, with the sky a solid dome made out of a shiny, brass-like substance. But this was the way everyone understood things at that time, so we don't begrudge Isaiah and Ezekiel of speaking of the "four corners of the earth" (Isaiah 11:12; Ezekiel 7:2), or Job for thinking the sky was a mirror (Job 37:18), or the Psalmist for thinking the earth stood still while the sun went around it (Psalms 93:1; Psalms 19:4-6).
The same principle holds true when examining the beliefs of earlier prophets about people of different races. Most nineteenth-century Latter-day Saints were raised in a world where all Black people were either slaves or illiterate poor. At the time there was much debate among American Christians in general as to how Blacks fit into God's overall plan as described in the Bible. Many theories abounded, with virtually all of them justifying, in one way or another, slavery or relegation of Blacks to the role of second-class citizens. There was even debate as to whether or not Blacks were human beings with souls that could receive salvation. (In contrast to this general Christian view, Joseph Smith declared rather progressively that yes, Blacks did have souls and could be saved.
Some LDS leaders were wary of the civil rights movement that started in the 1950s, and publicly stated their concerns
This continued into the twentieth century. Some LDS leaders were wary of the civil rights movement that started in the 1950s, and publicly stated their concerns. But there were differences of opinion among the brethren on this. At one end was Elder Ezra Taft Benson, who believed that the American civil rights movement was a front for communism; at the other was President Hugh B. Brown, who felt that the Church should publicly support the civil rights movement.
From our perspective as "enlightened" people of the early twenty-first century, virtually everyone in America up until the last few decades — prophets and other LDS leaders included — held beliefs that we could now consider racist. But that was the culture of the times, and we, like the rest of society, have progressed (line upon line, precept upon precept, see 2 Nephi 28:30) to become better people in this respect, more tolerant, more accepting. Fifty years from now, people will probably look back at our time and say, "How could they have been so bigoted?" Or, "How could they have missed issue X, which seems so clear to us now, in retrospect?"
The key point here is that the Lord works with the people who are available
The key point here is that the Lord works with the people who are available. He does not make them into radicals; he gives them just enough light and understanding to lift the Saints a little and make them more fit for the kingdom. In his mercy, God works with people where they are, and does not wait for them to be perfect before he will deign to speak to them.
Non-LDS Biblical commentators have noted this same tendency is present with Biblical prophets:
Though purified and ennobled by the influence of His Holy Spirit; men each with his own peculiarities of manner and disposition—each with his own education or want of education—each with his own way of looking at things—each influenced differently from another by the different experiences and disciplines of his life. Their inspiration did not involve a suspension of their natural faculties; it did not even make them free from earthly passion; it did not make them into machines—it left them men. Therefore we find their knowledge sometimes no higher than that of their contemporaries.
- John Dehlin, "Questions and Answers," Mormon Stories Podcast (25 June 2014).; Bill McKeever and Eric Johnson, Mormonism 101. Examining the Religion of the Latter-day Saints (Grand Rapids, Michigan: Baker Books, 2000), Chapter 16. ( Index of claims ); Simon Southerton, Losing a Lost Tribe: Native Americans, DNA, and the Mormon Church (Salt Lake City, UT: Signature Books, 2004) 10–11. ( Index of claims ); Watchman Fellowship, The Watchman Expositor (Page 3)
- Neil L. Anderson, Trial of Your Faith, Ensign (November 2012)
- Joseph Smith, Jr., Teachings of the Prophet Joseph Smith, selected by Joseph Fielding Smith, (Salt Lake City: Deseret Book Company, 1976), 269. off-site
- See Gregory A. Prince and Wm. Robert Wright, David O. McKay and the Rise of Modern Mormonism (Salt Lake City: University of Utah Press, 2005), chapter 4. ISBN 0874808227.
- James R. Dummelow, A Commentary on the Holy Bible: Complete in one volume, with general articles (New York : Macmillan, 1984 ), cxxxv.