Exterior of 'Muff' Lawler's barroom and residence, a Molly Maguire base, in the town of Shenandoah, Pennsylvania. From an old woodcut. The Molly Maguires was an Irish 19th-century secret society active in Ireland, Liverpool and parts of the Eastern United States, best known for their activism among Irish-American and Irish immigrant coal miners in Pennsylvania. After a series of often violent conflicts, twenty suspected members of the Molly Maguires were convicted of murder and other crimes and were executed by hanging in 1877 and 1878.