Brigham took over leadership and guided the exodus of 12-15,000 persons to Quincy, IL. On April 6, 1839 the prisoners were taken to Gallatin. While there, they requested a change of venue and escaped in transit, joining with the remnant leaving Far West for Illinois.
Mormons then built Nauvoo, Illinois, losing many to disease during their first year, including Joseph Smith, Sr., Joseph’s brother Don Carlos, and Joseph’s son Don Carlos. Brigham Young and other apostles were sent to England that summer (1839) for missionary duty. Brigham Young set up a highly efficient immigration system bringing thousands into Nauvoo from England.
In May 1845 the temple was completed and endowments were held up to the time of all departing Nauvoo the following year. The oath associated with the endowment is quite revealing. Elder Hyde said, "We were sworn to cherish constant enmity toward the United States Government for not avenging the death of Smith, or righting the persecutions of the Saints; to do all that we could toward destroying, tearing down or overturning that government; to endeavor to baffle its designs; to frustrate its intentions; to renounce all allegiance and refuse all submission. If unable to do anything ourselves toward the accomplishment of these objects, to teach it to our children from the nursery, impress it upon them from the death bed, entail it upon them as a legacy." A portion of the oath is as follows: "To obey him, the Lord's anointed, in all his orders, spiritual and temporal, and the priesthood or either of them, and all church authorities in like manner; that this obligation is superior to all the laws of the United States, and all earthly laws; that enmity should be cherished against the government of the United States; that the blood of Joseph Smith, the Prophet, and Apostles slain in this generation shall be avenged."
After the Mormons left, the temple was desecrated. It was torched in November 1848, and was finally destroyed by a tornado in 1850. In 2002 a newly-built replica opened there.
Part 1 of this series can be found here.
Part 2 of this series can be found here.
Part 3 of this series can be found here.
Part 5 of this series can be found here.