This is a very little bite, but an important one that, when misunderstood, leads to all kinds of difficulties in understanding the 19th century Mormon practice of plural marriage.
Bite 2: There was no formal, consistent “rule book” for the historical practice of plural marriage.
Once in a while the Lord apparently dictates in minute detail how his will is to be implemented by man: Genesis records the detailed dimensions and the materials to be used in constructing Noak’s ark and the tabernacle in the wilderness. Both Ether and I Nephi refer to detailed, inspired instruction on ship building. (The Lord is quite an engineer!)
In the more normal course of divine revelation, and certainly in our experience in the modern era, the Lord more often reveals eternal principles or general laws, and leaves it up to man, working under inspiration, to implement those principles in practical terms. So we have a commandment to preach the gospel to every nation, kindred, tongue and people – yet the details of the missionary program (who to send, at what age, for how long, under what organization, what to teach, how to teach, when to baptize, what to do in this and that contingency) is left to man to work out. We’re to raise our children in the Lord and prepare them for baptism at the age of accountability, but the Lord doesn’t spell out the day-to-day details; we’re left to come up with the nursery manual and the Primary program and the Family Home Evening program and the songs and the Friend, etc., in our attempt to follow the commandment.
Sometimes the details worked out by man remain in force indefinitely: Section 89 doesn’t define the “hot drinks” we are to abstain from, but an early sermon by Hyrum Smith identified those hot drinks as coffee and tea; the identification has been consistently upheld by succeeding prophets, and there is no reason I’m aware of for that identification to change. On the other hand, the practical day-to-day ways in which the Relief Society carries out its mandate to administer charity to those in want have changed according to the changing needs and times: in one era, that might mean collecting and sewing carpet rags for the comfort of those living with primitive heating; at another it might mean delivering babies and tending personally to a mother’s needs for a week or two; at another it might mean advocating for laws to protect the quality of the children’s milk supply; at another it might mean teaching a woman good nutrition and shopping habits, and helping her to practice those skills at a bishop’s storehouse. The principle is the same, but the “rules” and practices change over time.
The day-to-day practice of plural marriage in the 19th century falls into the “revealed principle, but work out the details yourself” category. There was no detailed and consistent “rule book” in place that governed how such marriages were contracted, how such marriages were lived, and how such marriages ended.
Perhaps one of the most widespread assumptions among modern Mormons discussing historical plural marriage is that the husband always had to ask the first wife’s permission to take another wife, and that the first wife always participated in the sealing. This is simply not true. There can be debate about whether permission should have been sought (and denial honored), and there may have been brief times when Joseph Smith, Brigham Young, and/or John Taylor encouraged or required that permission, but it simply cannot be assumed that permission was sought and given in any particular case, or that if a man surprised his existing family with a new wife he was breaking some law (well, he was breaking a law of trust and consideration and kindness, perhaps, but not a procedural law).
There are some existing sermons that require a man to arrange everything with a prospective bride’s father before approaching the woman. That, too, was a “rule” that was not consistent or long-lasting. I think it was, probably, an attempt to honor the patriarchal position of the father, but because it also had the potential effect of overruling the bride’s agency, it was not long or firmly practiced.
Some writers assert that the “rules” required a man to provide each wife with a separate house, or some territory within a common house over which she exercised domain, or other such provisions for daily life. Not so. What may have been practiced in one family was not a rule that all families were bound to live by. What may have been expected by custom in one town or one year was not applicable to other places and times. The existence of plural marriage among the Mormons simply lasted for too short a time for uniform practices to become established, in the absence of any rules dictated from either the Lord or the church president who held the keys to plural marriage.
Why does it matter?
Well, it helps us understand our ancestors better, without a layer of false assumptions between us and them. Ancestral marriages should be looked at on their own terms, without judging them by other marriages.
And maybe more importantly, we have a tendency to extrapolate from our limited understanding to reach indefensible conclusions. “Since thus-and-such was the rule in the 19th century, it means that in the eternities thus-and-such will happen, and I want no part of it!” Most of the conclusions people have drawn about assumed polygamy in the next life are based on misunderstandings of historical practices. Before we can address what might be true of the next world, we ought to be clear about what was true of this world.
Note: Although I’ve mentioned the next world, this is NOT the post to speculate about polygamy in the eternities. Please stick to comments and questions about the way it was practiced, and why, in the 19th century.