The Ancient Order of Hibernians is an Irish Catholic fraternal organization. Members must be male, Catholic, and either born in Ireland or of Irish descent. Its largest membership is in the United States, where it was founded in New York City in 1836.

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. This history remains part of local Pennsylvania lore and the actual facts are much debated among historians.