The Molly Maguires were members of a secret Irish organization. Many historians believe the "Mollies" were present in the anthracite coal fields of Pennsylvania in the United States from approximately the time of the American Civil War until a series of sensational arrests and trials in the years 1876−1878. Evidence that the Molly Maguires were responsible for coalfield crimes and kidnapping in the U.S. rests largely upon allegations of one powerful industrialist, and the testimony of one Pinkerton detective. Fellow prisoners also testified against the alleged Molly Maguires, but some believe these witnesses may have been coerced or bribed.[