The 19th Wife
By David Ebershoff. This multi-layered novel intertwines the story of Brigham Young's ex-wife Ann Eliza, a real historical figure who successfully campaigned to outlaw plural marriage in the United States, with a modern-day murder mystery in a polygamist Mormon splinter group. The narrative unfolds through fictional documents—correspondence, research papers, autobiographies—suggesting that truth is subjective and many-sided.
Source: http://www.amazon.com/19th-Wife-Novel-David-Ebershoff/dp/0812974158/