From the Bible, 1 Peter 2:18:[footnote]1 Peter 2:18 – Bible[/footnote]
18 Slaves, submit yourselves to your masters with all respect, not only to the good and gentle but also to the cruel.
Prelude to the National “Defense of Marriage” Campaign: Civil Discrimination Against Feared or Despised Minorities – D. Michael Quinn
Blacks and the Priesthood – Mormon Think
Black people in Mormon doctrine – Wikipedia
Statements about race in the Book of Mormon – Religious Tolerance
Race and the Priesthood Essay – LDS.org