The Pinkertons
By the 1850s, nearly all of the larger northern cities had organized police forces, including Boston, New York, Philadelphia, Baltimore, Chicago, Albany, Cincinnati, and New Orleans. All of these forces followed the Peel model; they were organized as bureaucracies, consisted of professional officers under a system of discipline, and had established rules of procedure. They also reported to a separate government authority.
Private police forces also emerged, organized by businesses to protect property and combat attempts at unionization. Among the many private police organizations probably the most famous was the Pinkerton Detective Agency. It was formed in the 1850s by Allan Pinkerton, who quickly found employment for his agents solving train robberies, which often took place outside the jurisdiction of existing police forces. It was through the railroads that Pinkerton’s fame grew.
Pinkerton solved train robberies which affected the Illinois Central Railroad, bringing him into contact with George B. McClellan, its president at the time, as well as giving him an opportunity to work with the company’s lawyer, Abraham Lincoln. When president-elect Lincoln was traveling to Washington to assume office the Pinkertons discovered and thwarted an assassination plot against him, and Lincoln continued to employ Pinkerton agents as bodyguards for a time.
The Pinkertons drew negative attention when the private police force was employed by companies in the decades following the Civil War, often to protect strikebreakers and to break up union protests. The negative publicity generated in many of these actions, in which Pinkerton operatives initiated violence against workers and their supporters, led to the US government passing the anti-Pinkerton Act in 1892, prohibiting the federal government from hiring Pinkerton agents as contractors.
Private police forces in the United States reached their peak in the period 1890-1920, beginning to wane as more modern police forces evolved in the smaller cities and towns of the nation. The role of protecting the president of the United States was taken over by the Secret Service, and many companies, though they maintained corporate security forces, no longer needed the services of a national independent police force.