Construction of rail lines in Wyoming such as the Union Pacific, the Burlington Northern, the Chicago, Burlington and Quincy, and the Chicago North Western created the need for railroad maintenance centers along their routes. This in turn created a need for qualified maintenance personnel to man the centers. Trainmen, enginemen, brakemen, switchmen, hostlers, conductors, firemen, machinists, and engineers [to name but a few] made valuable contributions to the safety and successful running of these freight and passenger lines. Many of these work groups organized into lodges or labor unions such as the Railway Shop Employees – Local Federation No. 105 in order to promote employee safety and fair wages. Railroad operators, lodges, and unions kept extensive records on their employees and/or membership. Some of the information collected such as seniority lists was organized into booklet form and distributed for employee use. Seniority lists were of major significance to employees of specialized work groups as they documented job tenure which, in turn, impacted salary and career advancement