Some of Joseph's wives were older women and some of them young, the youngest being Helen Mar Kimball who was 14.Although no evidence exists that Smith had or did not have sexual relations with Helen Mar, it is a practice in modern Polygamist groups to defer sexual relations in such a case.
Brigham Young famously said that after the doctrine was communicated to him, he would gladly have traded places with the body in a hearse he saw passing down the street, than embrace this new doctrine. Bennett, was excommunicated for the adulterous practice of "spiritual wifery." Some of those who left or were driven from the Church set out to expose Smith and his alleged corruption.
Eventually this antagonism led to Joseph surrendering himself to jail for charges of riot and treason.
However, a few members continued to practice plural marriage privately with the approval of a few Church leaders until a second proclamation was issued by the Church in the early 1900s.
Under that proclamation, those who continued to practice it became subject to excommunication from the Church.
Some Mormon leaders at the time voiced their objection to the practice and left the Church.