The Molly Maguires were members of an Irish-American secret society

Secret society

A secret society is a club or organization whose activities and inner functioning are concealed from non-members. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence agencies or guerrilla insurgencies, which hide their...

, whose members consisted mainly of coal miners. Many historians believe the "Mollies" were present in the anthracite coal

Anthracite coal

Anthracite is a hard, compact variety of mineral coal that has a high luster...

 fields of Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

 in the United States from approximately the time of the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 until a series of sensational arrests and trials in the years 1876−1878. The Molly Maguires were accused of kidnapping and other crimes, largely because of the allegations of one powerful industrialist (Franklin B. Gowen

Franklin B. Gowen

Franklin Benjamin Gowen served as president of the Philadelphia and Reading Railroad in the 1870s and 1880s....

), and the testimony of one Pinkerton

Pinkerton National Detective Agency

The Pinkerton National Detective Agency, usually shortened to the Pinkertons, is a private U.S. security guard and detective agency established by Allan Pinkerton in 1850. Pinkerton became famous when he claimed to have foiled a plot to assassinate president-elect Abraham Lincoln, who later hired...

 detective (James McParland

James McParland

James McParland,There are various spellings of James McParland's name. His stenographer, Morris Friedman, wrote a book about him — as "McParland." The Pinkerton Labor Spy, New York, Wilshire Book Co., 1907). also known as James McParlan,The Corpse On Boomerang Road, Telluride's War On Labor...

).