The railroads invented the career path in the private sector for both blue-collar workers and white-collar workers. Railroading became a lifetime career for young men; women were almost never hired. A typical career path would see a young man hired at age 18 as a shop laborer, be promoted to skilled mechanic at age 24, brakemen at 25, freight conductor at 27, and passenger conductor at age 57. White-collar careers paths likewise were delineated. Educated young men started in clerical or statistical work and moved up to station agents or bureaucrats at the divisional or central headquarters. At each level they had more and more knowledge, experience, and human capital. They were very hard to replace, and were virtually guaranteed permanent jobs and provided with insurance and medical care. Hiring, firing, and wage rates were set not by foremen, but by central administrators, to minimize favoritism and personality conflicts. Everything was done by the book, whereby an increasingly complex set of rules dictated to everyone exactly what should be done in every circumstance, and exactly what their rank and pay would be. By the 1880s the career railroaders were retiring, and pension systems were invented for them.