Mary Harris "Mother" Jones was a fearless fighter for workers' rights who shaped the concept of "rank-and-file unionism." When she was mocked as the "grandmother of all agitators," in the U.S. Senate, Mother Jones replied that she would someday like to be called "the great-grandmother of all agitators." And she is. She taught us that movements are theatres of battle, that strategy matters, and that unions can be vehicles for workers' power, not just a contract.