William Victor Smith comments on the primary purpose of polygamy in Joseph's 1844 sermon.
William Victor Smith, Textual Studies of the Doctrine and Covenants: The Plural Marriage Revelation (Salt Lake City: Greg Kofford Books, 2018), 137
In this sermon, Smith outlines what may have been his primary purpose in polygamy: the establishment of sealing networks, in which families were joined to each other through sealing bonds that guaranteed salvation to those sealed to him. In that light, one can somewhat understand why some women—or their families through them, like fourteen-year-old Helen Mar Kimball, daughter of Heber and Vilate Kimball—might desire to be joined to Smith. Heber Kimball placed considerable pressure on Helen to be sealed to Smith, and the motivation was likely to cement a connection to Smith. The (virtually unbreakable) sealing link to Smith, whose exaltation was assured, meant that Kimball’s family had staked a claim in the glory of the hereafter.