What was the Purpose of Mormon trail?
The Mormon Trail's purpose was to lead the Mormons to the Great Salt Lake Valley.
The Mormon Trail was traveled by Mormon Pioneers from Illinois to Utah after they had been kicked out of Illinois. It was then traveled by Mormon converts from Europe and Canada as they immigrated to "Zion" (the Mormon settlements in Utah). The trail was mostly discontinued after the railroad reached Salt Lake City.
It was the emigrant trail that began at the Missouri River and took the settelers to what is now California. The eastern half of it overlapped the Oregon Trail and the Mormon Trail. It was also the favored route used by the 49ers in the Gold Rush and existed from 1845 to 1869 when the Transcontinental Railway was completed.
Brigham Young lead the first group of Mormon pioneers along the Mormon Trail to Utah in 1846-47. Subsequent groups came over the next 25 years lead by various experienced trail guides. The Mormon Trail followed a similar route to the Oregon Trail until Wyoming, when it went south to Utah rather than north to Oregon.