The Mormons, of course, met many traders, freighters, trappers and mountain men at their various points of departure and along the Mormon Trail. Additionally they encountered other westering Americans, the military, including discharged soldiers and even deserters and draft-dodgers from both north and south (during the Civil War, sometimes Mormon trains were even stopped and searched for such men), mail carriers, 49ers, Overland Telegraph workers, government roads workers, and Union Pacific Railroad workers.
During the Civil War, some of the Mormon trains were stopped, usually near Fort Bridger (Wyoming), and all native born males eighteen years or older had to take an oath of allegiance to the United States, while all male aliens eighteen years or older had to swear to act in strict neutrality"Source: Historic Resource Study - Mormon Pioneer National By Stanley B. Kimball, Ph.D., May 1991. (The study focuses on the history of the trail from its official beginning in Nauvoo, Illinois, to its terminus in Salt Lake City, Utah, during the period 1846-1869. During that time, thousands of Mormon emigrants used many trails and trail variants to reach Utah. This study emphasizes the 'Pioneer Route' or 'Brigham Young Route' of 1846-1847. The sections on Mormon beliefs and motivations for going west have been omitted. Interested persons can find ample sources for that information. The footnotes, bibliography, maps, pictures, pioneer companies by name and dates for the 22-year period, and historic sites - about 2/3 of the book - have also been left out for space considerations. Thanks to Dr. Kimball and the National Park Service for the availability of this information.)