The first settlers in the Salt Lake Valley were members of The Church of Jesus Christ of Latter-day Saints, sometimes called Mormons because of their belief in the Book of Mormon. They had suffered persecution in New York, Ohio, Missouri, and Illinois. After a mob killed their church founder, Joseph Smith, in 1844, most church members followed the leadership of Brigham Young and the Council of the Twelve Apostles. Beginning in February, 1846, many Latter-day Saints moved from Nauvoo, Illinois, to a temporary camp in eastern Nebraska called Winter Quarters. Young led an advanced party of 143 men, three women, and two children that set out for the Rocky Mountains in April 1847. Traveling parallel to the Oregon Trail along the Platte and North Platte Rivers to Fort Laramie, they proceeded on the Oregon Trail to Fort Bridger, and from there followed the route taken by the Donner-Reed pioneers in 1846. Brigham Young, sick with mountain fever, was among the last of this party to enter the Salt Lake Valley, where he arrived on July 24, 1847. Many pioneer companies reached the valley over the next few years. Before the transcontinental railroad was completed in 1869, some eighty thousand emigrants traveled to Utah using various conveyances, including ox teams and handcarts. At this place, President Young, still feeble from his illness, was riding under the cover of Elder Woodruff's carriage, and when the teams halted he came to the front, looked over the country before him, swung his hat, shouted, "Hurrah! Hurrah! Hurray!!!" and then said to Heber C. Kimball, "Brother Heber, this is the place."