Louisa Beaman: Joseph Smith's First Plural Wife in Nauvoo (1815–1850)

Louisa Beaman (7 February 1815 – 1850), daughter of Alvah Beaman and Sarah Burtts of Livonia, was the first plural wife sealed to the Prophet Joseph Smith in Nauvoo. The 1841 ceremony was performed in secrecy—Louisa wore a trench coat and a hat as a disguise—and it was a sacred, costly act of faith in the restored principle the Prophet had been commanded to restore. After the martyrdom of Joseph and Hyrum, Louisa was sealed to Brigham Young and journeyed west with the Saints, dying in Utah in 1850. Her life is a faith-promoting witness of the early Saints who, at great personal cost, accepted the principles the Lord revealed through His prophet and gave their whole lives to the building up of Zion.

Fuller account of this event (the complete account as preserved in Joseph Smith Foundation, 'Louisa Beaman'):

Sister Louisa asked the Lord in fervent prayer for a testimony concerning the principle. The Lord heard her supplication and granted her request, and after being convinced that the principle had emanated from God, she accepted it, and was married to the Prophet Joseph Smith.