The beginning of the evacuation of Nauvoo, Illinois, was planned for March–April, but because of mob threats President Brigham Young directed that the exodus of the Saints across the Mississippi River begin on February 4, 1846. President Young remained behind to administer endowments to the Saints and did not leave Nauvoo until mid-February.
Significant Events: Before his death the Prophet Joseph Smith prophesied, “Some of you will live to go and assist in making settlements and build cities and see the Saints become a mighty people in the midst of the Rocky Mountains.” Nearly 12,000 Saints departed Nauvoo from February to September 1846. After the Saints left Winter Quarters and later locations, they were organized into companies of tens, fifties, and hundreds, under a company captain (D&C 136:3). In September 1846 a mob of approximately 800 men equipped with six cannons laid siege to Nauvoo. After several days of fighting, the remaining Saints were forced to surrender in order to save their lives and gain a chance to cross the river. Five to six hundred men, women, and children crossed the river and camped on the riverbank. President Brigham Young sent rescue teams with supplies to evacuate these “poor Saints.”