Mary Harris “Mother” Jones, the storied Irish-born labor organizer, trained public attention on the scourge of child labor and energized efforts to end it by law. In 1914, during her work in support of striking coal miners in Ludlow, Colorado enforcing the 8-hour work day, President Theodore Roosevelt called Mother Jones the most dangerous woman in America. She was 83 years old at the time. Born in Ireland in the 1830s, her exact birthdate is unknown; her baptism was recorded on August 1, 1837.