From Richard N. Ostling's "What is Mormonism" opinion piece in today's Washington Post:
"... even the story about the (Mormon) church's founding is unusual to nonbelievers: God appeared to Joseph Smith and told him that all existing forms of Christianity were "an abomination" and then directed Smith to a hillside in upstate New York where, with the help of the angel Moroni, Smith recovered a set of golden tablets that revealed the real word of God. Smith had further revelations, which Mormons treat as scripture alongside the Bible, including that Jesus would eventually return to reign from Missouri."
...
"In addition to the problematic history of polygamy and the church, there is a second discarded teaching, on race, that has lingered for some in their thinking about Mormonism. Until 1978, the Mormons barred anyone with African blood from the church's "priesthood," to which virtually all men and boys eventually belong."