Pros
Union Pacific Railroad has been around since 1861 and is a stable company. Even during tough economic times, there is still a need for rail service, so the railroad will be around for the foreseeable future. Because of a combination of union (agreement) and managers (non-agreement), the pay for all jobs is quite high in comparison to clerical and lower- to middle-level management positions in other companies. If you are comfortable in a semi-structured office environment, Union Pacific is the place to be.
Cons
The company tends to be too rigid in structure and a bit top-heavy with upper management. Also, nepotism has been and continues to be an issue--especially as one climbs the corporate ladder. The management or "non-agreement" clashes often with the union or "agreement" employees, which causes conflict and resentment to occur frequently in departments where there are both types of employees. In addition, the process for applying for promotions can be very involved--even for lateral moves. Often, depending on the position, there will be multiple interview appointments, with multiple interviewers, where the candidates are scored on a subjective point system. This will sometimes result in the lesser candidate being awarded the position--especially if the interviewers happen to personally know one candidate and not the other.