After the martyrdom of Joseph Smith, religious persecution in Nauvoo had been increasing, and the leaders of the Church decided in 1846 that it was time to leave and search for a place where they could practice their religious beliefs freely. The plan was to leave in the Spring, but increased animosity toward the Mormons forced them to leave earlier. On February 4, 1846, 3,000 Mormon pioneers left Nauvoo in what is referred to as the Great Exodus. The first part of the journey, which covered only about 256 miles, was difficult because of heavy rains and mud. The group had planned on making it all the way to Utah before winter, but the difficulty of the journey from Nauvoo to Nebraska took so long that this was not possible.
These first pioneers ended up setting up a settlement in Nebraska for the winter and called it Winter Quarters. The winter was harsh, and the pioneers only had makeshift homes. More than 400 people lost their lives in the horrible conditions of Winter Quarters. Spring brought welcome relief to the suffering population. On April 5, 1847 Brigham Young led the first wagon train out of Winter Quarters. The train was made up of 148 people, 72 wagons, and many livestock. For the first part of the journey the Mormon pioneers followed the Oregon trail which followed the Platte River to Fort Bridger.
The first group of pioneers to leave were mindful of those who had been delayed because of sickness or lack of funds. They improved the trail as they went, and established small settlements with a few buildings and planted crops.
At Fort Bridger the pioneers left the Oregon Trail. Instead they followed a trail that led to California and went through Utah. This section of the journey was 116 miles and was probably the hardest part of the trail because they had to get over the Wasatch Range, which was filled with canyons and steep passes. Making it even more difficult was the fact that they were already tired from traveling the 1,000 miles to get to this point.
On July 24, 1847, the first wagon train entered the Salt Lake Valley. The work was not over though. The "saints" immediately began planting crops and building up a city. They also had to provide for those that would be following. In 1869, after encouragement from Church leaders, the transcontinental railroad was completed. This made travel to the Salt Lake Valley much easier, and use of the Mormon Trail was discontinued.