How can you learn what your ancestor did for a living?
See article in Ancestry Magazine May/June 2005 vol. 24 no. 1 pp. 16-23
Reference book: Directory of North American Railroads, Associations, Societies, Archives, Muesums and Their Collections., compiled by Holly T. Hansen, 1989. (find in a library)
The U.S. Rail Road Retirement Board has a web site with information on how to locate and obtain Rail Road Pension Records
Occupation not an honorable one? Try Black Sheep Ancestors