So why did he (Joseph Smith) have 34 wives?
http://en.wikipedia.org/wiki/Joseph_Smith%2C_Jr.
Smith was married to approximately 33 women besides Emma.[48]In the group of Smith's well-documented wives, eleven (33 percent) were 14 to 20 years old when they married him. Nine wives (27 percent) were twenty-one to thirty years old. Eight wives (24 percent) were in Smith's own peer group, ages thirty-one to forty. In the group aged forty-one to fifty, there is a substantial drop off: two wives, or 6 percent, and three (9 percent) in the group aged fifty-one to sixty. [49]
Although Smith fathered several children with Emma, no additional offspring from any of the women making a "plural wife" claim has ever been proven,[50] and in fact of the approximately twelve children of these wives that were claimed to have been fathered by Joseph Smith, five so far have been conclusively shown as genetically unrelated, through DNA analysis of living descendants.[51] Work is ongoing to determine paternity or non-paternity of the remaining individuals.
In official church publications, Smith publicly denied such doctrines existed.[52] During Smith's lifetime, his wife Emma reportedly "vacillated between acceptance and rejection" of the practice,[53] with Emma even attending the marriage of Smith to at least one of his plural wives.[54] However, Emma died denying that her husband ever had any other wives, as did Smith's eldest son Joseph. Emma Smith's deathbed testimony stated "no such thing as polygamy, or spiritual wifery, was taught, publicly or privately, before my husband's death, that I have now, or ever had any knowledge of... He had no other wife but me; nor did he to my knowledge ever have."[55] However, one modern commentator has stated that due to Emma's opposition to plural marriage, Smith "moved ahead surreptitiously", resulting in Emma's being unaware of the existence of many of Smith's plural wives.[
