Contrary to conventional wisdom, the Mormon disdain for the symbol was more of a late development in Church history, emerging at the grassroots around the turn of the 20th century, and was institutionalized in the 1950s under the direction of President David O. McKay, on grounds that it was a Catholic symbol. Prior to this time, many Latter-day Saints (including Church authorities), embraced and promoted the symbol of the cross.
My book, Banishing the Cross: The Emergence of a Mormon Taboo (John Whitmer Books, 2012) traces the development of LDS attitudes toward the symbol, and shows that the aversion to the cross in Mormon culture actually began as a means to disassociate the Church from Catholicism. The book includes many 19th-century photos of the cross being worn as jewelry, stitched it into quilts, framed and hung on walls, incorporated into funeral floral arrangements, etc. Perhaps most interesting of all, I explore in detail the LDS Church's 1916 Ensign Peak cross monument proposal—-a proposal to the Salt Lake City Council that stirred great controversy within and outside the Church.