Allan Pinkerton was born in Glasgow in Scotland in 1819. A cooper by trade he was active in the Chartist movement as a young man. Disillusioned by the failure to win universal suffrage, Pinkerton emigrated to the United States.
Pinkerton settled in Chicago and became a deputy-sheriff. In 1852 he formed the Pinkerton Detective Agency. The first detective agency in the United States, it solved a series of train robberies. In 1861 the agency was given the task of guarding Abraham Lincoln. While in Baltimore, while on the way to the inauguration, Pinkerton foiled a plot to assassinate the president.
The Pinkerton Detective Agency was a great success. On the facade of his three-story Chicago headquarters was the company slogan, "We Never Sleep". Above this was a huge, black and white eye. The Pinkerton logo was the origin of the term private eye. Pinkerton became head of the American secret service during the Civil War and led the pursuit for Jessie James.
In 1873 Franklin B. Gowen, president of the Philadelphia & Reading Railroad, had a meeting with Allan Pinkerton. Gowen had considerable investments in the coal-mines of Schuylkill County and feared that the trade union activities of John Siney and the Workingmen's Benevolent Association would result in lower profits.
Allan Pinkerton decided to send James McParland to Schuylkill County. Assuming the alias of James McKenna, he found work as a labourer in Shenandoah. Soon afterwards he joined the Workingmen's Benevolent Association and the Shenandoah branch of the Ancient Order of Hibernians (AOH), an organisation for Irish immigrants run by the Roman Catholic clergy.
After a few months of investigations McParland reported back to Allan Pinkerton that some members of the Ancient Order of Hibernians were also active in the secret organization, the Molly Maguires. McParland estimated that the group had about 3,000 members. Each county was governed by a bodymaster who recruited members and gave out orders to commit crimes. These bodymasters were usually ex-miners who now worked as saloon keepers.
Over a two year period James McParland collected evidence about the criminal activities of the Molly Maguires. This included the murder of around fifty men in Schuylkill County. Many of these men were the managers of coal mines in the region.
John Kehoe, one of the leaders of the Molly Maguires became suspicious of McParland and began to investigate his past. McParland was tipped off that Kehoe was planning to murder him so he fled from the area.
In 1876 and 1877 James McParland was the star witness for the prosecution of John Kehoe and the Molly Maguires. Twenty members were found guilty of murder and were executed. This included Kehoe, a former union leader who was convicted of a murder that had taken place fourteen years previously.
After Allan Pinkerton died in 1884, the Pinkerton Detective Agency was run by his two sons, Robert Pinkerton and William Pinkerton. The brothers opened their fourth office in Denver. They appointed James McParland and Charlie Siringo to run the Pinkerton's western division.