Two years later, Smith's successor, Brigham Young, led an exodus of persecuted Latter-day Saints from Nauvoo along the western wagon trails in search of a sanctuary in “a place on this earth that nobody else wants.” The expedition, more than 10,000 pioneers strong, set up camp in present-day western Iowa while Young
It was the civilians. Mainly New York. It was because they couldn't accept the Mormon religion specifically the fact that they were allowed to have multiple wives. Which was not a thing the Christians in the east liked.
Explanation:
They had a much different religion. Because of this they were out casted. I mention New York specifically because that's where most came from. When they heard about free land and gold in the west, they decided to head west where they can start their own community.
