Mary Harris was born in Ireland in 1837. She and her family moved to Toronto when she was a young girl, shortly after her grandfather was hanged by the British for being part of the Irish Republican Movement.
When she finished school, Harris moved to the U.S., where she worked as a seamstress in Chicago and a teacher in Michigan. She met her husband, George Jones, through union involvement, and they married in 1861. The couple quickly had four children.
In Tennessee in 1867, Jones' husband and children died during the Yellow Fever Epidemic. After her family died, Jones moved to Chicago and became a dressmaker. A few years later, in 1871, she lost all of her property in the Great Chicago Fire. These two events are said to be the ones that shaped Jones' later life. Needing an income, she was employed by the Knights of Labor, a precursor organization to the Industrial Workers of the World (IWW), which Jones helped to found in 1905. In the course of her labor work in the late 1800s, Jones was heavily involved in United Mine Workers' activities, as well as in the Socialist Party of America.
One aspect of organizing for which Jones is particularly noted in the organization of the wives and children of workers, particularly mine workers, and child workers themselves. In 1903, she organized a "Children's Crusade," in which children who worked in mills and mines marched from Kensington, Pennsylvania to Oyster Bay, New York (the home of president Theodore Roosevelt). The children held signs reading "We want time to play" and "We want to go to school." Though Roosevelt largely ignored the protest, it did bring the issue of child labor to the forefront of public (and union) thought.
In the early part of the 1900's, Mother Jones continued to organize both adults and children and was subsequently hassled by the police and the government, put under house arrest, charged with crimes, attacked by hired thugs, and even serving some time in prison. Corporations she had organized against also sued her for slander and libel. In 1925, when men broke into the house she where she was staying and attacked her, Jones fought them both off. One man later died from his wounds. Jones was 88 years old.
Mother Jones continued her organizing work up until her death in 1930, at the age of 93.