Question: Alexander Campbell, was a tavern owner, who, with three other convicted, was hanged for the murders of two mine operatives, which  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?
Sentence (from "Molly Maguires"): 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.
Relevant evidence: No