Magón and other PLM members had organized a brigade of revolutionaries in Douglas, Arizona in the years preceding his move to Los Angeles. An expedition was sent to the Cananea copper mines about thirty miles from the southern border of Arizona with the alleged intention of exterminating all Americans employed in and about the mines. The brigade had been pursued by the Arizona Rangers who put them to flight, capturing a few of them. Magón and his companions were extradited to Tombstone, Arizona where they were charged with violating U.S. neutrality laws. Although the American and Mexican left rallied to their defense, they were convicted and sentenced to eighteen months in Yuma Territorial Prison, later being transferred to Arizona State Prison Complex – Florence. They were released in 1910 and again resumed publishing "Regeneración" from an office in downtown Los Angeles. The Mexican civil war began that same year, and the "Magonistas", as the PLM forces were known, were involved in combat throughout Mexico, along with the forces of Pancho Villa, Emiliano Zapata and Venustiano Carranza and Francisco I. Madero.