Fanny Alger
Note, an update coming to this page and others
Fanny Alger - Joseph Smith's First Plural Wife
Plural marriage is one principle of celestial or eternal marriage. However, when allowed by God, polygamy for time could be practiced. Joseph was married to three widows who were sealed to their deceased husbands. Similarly, his plural marriage to Fanny was not an eternal marriage.
Additional Resources:
The Joseph Smith–Fanny Alger Relationship: Plural Marriage or Adultery?