Wow Bob. Thanks!
The third article, on the history of the railroad police, is an incredibly thorough historical treatment.
A theme throughout seems to be that the railroads didn't hire men and call them "railroad police". They hired them and called them something less "offensive", such as Railroad Agents or Railroad Detectives. Clearly though, they were well armed and given a license to kill.
Given the huge economic benefits brought by the railroads to any state or region, it appears that the State Governors and the Federal Government turned a blind eye to this.
Also interesting is that the Pinkerton Agency seems to have been catapulted into wealth and fame in large part due to the hirings and support by the railroads, who had endless cash flow. It almost sounds as if the railroad Pinkertons were the 19th century precursors to the FBI, since they were apparently granted the power by the Federal Government or State Governors to investigate crimes and arrest people in any part of the country.
Mannyrock
