The very exclusive and secret nature of marriage in the LDS Church was not practiced in the early days of the religion:

“[W]e believe, that all marriages in this church of Christ of Latter Day Saints, should be solemnized in a public meeting, or feast, prepared for that purpose: and that the solemnization should be performed by a presiding high priest, high priest, bishop, elder, or priest, not even prohibiting those persons who are desirous to get married, by other authority… All legal contracts of marriage made before a person is baptized into this church, should be held sacred and fulfilled.”

Appendix 3: Statement on Marriage (Kirtland, OH: The Church of Jesus Christ of Latter-day Saints, circa 1835), 251; verses 1 and 4 (Emphasis added).

The teachings of the Church soon became so diametrically opposed to this notion that it was eventually removed, but not until forty years later, in 1876.

Not only were the marriage rituals of the temple ceremony established during this time (1835-1876) so as to make marriage nothing like a “public meeting, or feast” but the notion that other marriages “should be held as sacred and fulfilled” was also disregarded, as LDS Leaders (including Joseph Smith and Brigham Young) married wives of other men, stating that the secular marriages were invalid in the sight of God.

“All legal contracts of marriage made before a person is baptized into this church, should be held sacred and fulfilled” is a peculiar idea, isn’t it? If you think of the natural opposite of this phrase, you could determine that “any marriage made after a person is baptized into the church should not be held as sacred or fulfilled.”

This seems to have been inserted as a pretext for marital disregard and sexual plunder.