The entire following section is from with minor edits.

Why were these wanted posters made for the LDS leaders of the Church? Because polygamy was illegal.

Isn't One Wife Enough? by Kimball Young, p. 396.

"The benefits derived from the righteous observance of this order of marriage do not accrue solely to the husband, but are shared equally by the wives; not only is this true upon the grounds of obedience to a divine law, but upon physiological and scientific principles. In the latter view, the wives are even more benefitted, if possible, than the husband physically. But, indeed, the benefits naturally accruing to both sexes, and particularly to their offspring, in time, say nothing of eternity, are immensely greater in the righteous practice of patriarchal marriage than in monogamy, even admitting the eternity of the monogamic marriage covenant."

Critic's point:Only people performing illegal acts need to go to such lengths to avoid the law.

, Section CI, p. 251, Book of Commandments, Joseph Smith Papers

Critic's note:The Church Almanac lists Parley P Pratt as assassinated while on a mission but he was really murdered by the irate existing husband of his latest fancy. Technically therefore, she was polyandrous also. Practically, she was adulterous and then when she married Parley, bigamous. She was never divorced from her first husband. She had just abducted one of her children. Her husband took the child back after a court hearing and then killed Parley. I don't think he was ever tried for the murder which was in Arkansas. The Mountain Meadows Massacre was one later result of the ensuing hatred by Brigham et al of people from that area. The brethren did not recognize any marriage they did not perform as being legal, so they took whom they pleased. Missions were often wife gathering expeditions. Moral of the story: Better be careful whose family you try to steal…you might just get yourself killed!

Times and Seasons (LDS-owned newspaper):

This first interview had a similar effect to a sudden shock of a small earthquake. When he found (after the first outburst of displeasure for supposed injury) and I received it meekly, he took the first opportunity to introduce Sarah Ann to me as Joseph's Wife. This astonished me beyond measure.

In Joseph Smith's time, monogamy was the only legal form of marriage in the United States.

, Section CI, p. 251, Book of Commandments, Joseph Smith Papers

Within days of his election, controversy brewed as he was charged with being "one of a self-perpetuating body of fifteen men who, constituting the ruling authorities of the Church of Jesus Christ of Latter-day Saints, or 'Mormon' Church, claim, and by their followers are accorded the right to claim, supreme authority, divinely sanctioned, to shape the belief and control the conduct of those under them in all matters whatsoever, civil and religious, temporal and spiritual."

Estimates of the number of these sealings range from 12 to 14.

In January 1904, Senator Smoot prepared a rebuttal to these criticisms with the help of several non-Mormon lawyers. The actual hearings began in March. Mormon President Joseph F. Smith took the witness stand and was interrogated for three days. Apostles Matthias F. Cowley and John W. Taylor did not show up after being subpoenaed. Apostle Marriner W. Merrill ignored one subpoena and died soon after being subpoenaed a second time. Taylor fled to Canada. Other witnesses included James E. Talmage; Francis M. Lyman, president of the Quorum of the Twelve at the time; Andrew Jensen, church historian; B. H. Roberts; and Moses Thatcher, who was dropped from the quorum in 1896.

from the LDS website (also see footnote #24).

Prior to being called as an apostle of The Church of Jesus Christ of Latter-day Saints, Smoot had run for a Senate position, but withdrew before the election. After becoming an apostle in 1900, he received the approval of church president Joseph F. Smith to run again in 1902 as a Republican. In January 1903, the Utah legislature chose him with 46 votes, compared to his Democratic competitor, who won 16.

Journal of Discourses, Vol. 2, pp. 13-14.

The attorney who represented those protesting Smoot's admittance to the Senate, Robert W. Tayler, explained in his summation that polygamy was irrelevant and the real danger was Mormon belief in revelation. Although it has been claimed that polygamy was largely responsible for deep animosity between the LDS Church and the United States, in reality, it became a cause celebre to help unite Republicans against Democrats. Earlier, when it was well known that Brigham Young was a polygamist, the US President appointed him twice as territorial governor and the Senate ratified the appointment.[citation needed] Much of the American Protestant establishment viewed the LDS Church with distrust. The establishment was also skeptical of Utah politics, which before gaining statehood in 1896 had at times been a theocracy (theodemocracy) and in the early 20th century was still heavily dominated and influenced by the LDS Church.