How old was Joseph Smith's youngest wife?

Some of Joseph Smith's polygamous marriages were to young women.

Is there polygamy in heaven? Why don't we know exactly how many wives Joseph had? The documentation for Joseph's plural marriages is limited, so historians disagree over which women were actually wives. Did Joseph have sex with his plural wives? Yes, probably with at least some of them. There are varying degrees of evidence that Joseph likely had sexual relations with some of his plural wives (see below). Plural Wives of Joseph Smith Name of Wife Date of Marriage to Joseph Smith Age at Time of Marriage (Years) Evidence for Sexuality Fanny Alger ca. 1833–1836 ca. 17–19 Moderate Louisa Beaman April 5, 1841 26.2 Strong Zina Diantha Huntington† October 27, 1841 20.9 None Presendia Lathrop Huntington† December 11, 1841 31.3 None Agnes Coolbrith January 6, 1842 29.6 None Mary Elizabeth Rollins† February 1842 23.10 None Patty Bartlett† March 9, 1842 47.1 None Eliza R. Snow June 29, 1842 38.5 Weak Delcena Johnson ca. pre-July 1842 35.8 None Sarah Ann Whitney July 27, 1842 17.4 Weak Martha McBride August 1842 37.5 None Sylvia Sessions† ca. November 1842–May 1843 ca. 24.4–24.10 Weak Ruth Vose† February 1843 35 None Flora Ann Woodworth Spring 1843 ca. 17–18 None Emily Partridge March 4, 1843 19.1 Strong Eliza Partridge March 8, 1843 22.11 Moderate Almera Johnson April 1843 30.6 Strong Lucy Walker May 1, 1843 17 Moderate Marinda Nancy Johnson† May 1843 24.11 None Maria Lawrence ca. May 1843 19.5 Moderate Sarah Lawrence ca. May 1843 17 Moderate Helen Mar Kimball ca. May 1843 14.9 None Hannah Ells ca. Summer 1843 ca. 35.5 Weak Olive G. Frost ca. Summer 1843 ca. 27 Weak Elvira Cowles† June 1, 1843 29.7 None Rhoda Richards June 12, 1843 58.10 None Desdemona Fullmer July 1843 33.9 None Malissa Lott September 20, 1843 19.9 Strong Fanny Young November 2, 1843 56 None Elizabeth Davis† Unknown ca. 51–52 (?) None Sarah Kingsley† Unknown ca. 54–55 (?) None Lucinda Pendleton† Unknown ca. 31–37 (?) None Nancy Maria Winchester Unknown ca. 14–15 (?) None Esther Dutcher† Unknown ca. 38–39 (?) None Mary Heron† Unknown ca. 38–39 (?) Weak † Legally married to another husband at the time of sealing to Joseph Smith. See the chart below for further details. Who was Joseph's first plural wife? Probably Fanny Alger, though not all historians agree that Fanny was a legitimate plural wife. Who was Fanny Alger? Is it true Joseph married teenagers? Yes. Joseph was sealed to about ten women who were between the ages of 14 and 20 at the time of their marriage. Was marrying teenagers common in Joseph's day? Yes. In contrast to today, marriage of teenagers to older men was relatively common and not considered a social taboo in nineteenth-century America. For example, the 1850 U.S. Census indicated that about 25% of women married in the West-South Central region were 15–19 years old. Marriage age gaps averaged between 4 and 7 years depending on the region, whereas age gaps today are about 2.5 years.

When I learned about the “law of adoption,” “dynasty sealings,” and “eternity only” sealings, the once salacious headlines regarding polygamy in the early church lost its shock value. For example, Joseph Smith’s youngest polygamist wife was 14-year-old Helen Mar Kimball. Though marriage at 14 would have been more acceptable on the frontier in the 1840s, that is still fairly young. However, Helen reports that she was sealed to the prophet at the behest of her father, Heber C. Kimball, who had “a great desire to be connected with the prophet.”16 These details line up with what I’ve come to understand about the “law of adoption.” Further, there is very little evidence to support the claim that Joseph Smith had sexual relations with Helen.17