The Molly Maguires (Mollies) were a secret Irish organisation, the exact origin of which is disputed. The Mollies appear to have come into existence in rural Ireland as a means of violently redressing injustices by land owners and unfair legal practices. It is difficult to say whether there was an actual Molly Maguire, or whether she is simply a representative of the suffering of 'mother Ireland', making the practice of her followers cross-dressing as 'Molly' a form of symbolic disguise.
After the Great Irish Famine of 1845-1852, and the mass emigration that followed, Molly Maguire gangs began to appear in areas to which the Irish had spread, including Pennsylvania in the United States, where they were responsible for a series of crimes and kidnappings motivated by unfair working conditions in the coalfields. The Pennsylvania Molly Maguires became the subject of a 1970 film by Martin Ritt, starring Sean Connery.