On an ex-Mormon discussion board recently, the question was posed: What was the tipping point that caused you to leave Mormonism? (I asked the same question, but called it a “point of departure” in my book, Why We Left Mormonism (Baker Book House.)
One person said it was because of Fanny Alger, a young woman who lived in Joseph Smith's household and who became his first plural wife– without the knowledge nor consent of Emma, his wife.
When I was a Mormon, even at BYU we were taught that Joseph Smith did not have any wives other than Emma. Mormons of my generation would never have believed that Smith would have slept with underage girls.
But he did. Some as young as 14 years of age. And some, older ones, who had living husbands at the time Smith “married” them.
For more information about this, see the documentation and chart online.
For more information, see The Mormon Mirage 3rd Edition: A Former Member Looks at the Mormon Church Today(Zondervan, 2009). Also available as an audiobook and as an expanded-text E-book for Nook, Kindle and other reading devices.
You can also read about Mormonism as practiced today in Latter-day Cipher (Moody, 2009).