Mary Kenney O'Sullivan (January 8, 1864 – January 18, 1943), was an organizer in the early U.S. labor movement. She learned early the importance of unions from poor treatment received at her first job in dressmaking. Making a career in bookbinding, she joined the Ladies Federal Local Union Number 2703 and organized her own group from within, Woman's Bookbinding Union Number 1. Her women's bookbinding union became a branch of the American Federation of Labor (AFL) and she went on to become a full-salaried organizer. Though she would not hold the position for long she is remembered as being the first woman AFL employed on a full salary. She was a member of the Jane Addams's settlement house movement, moving into Hull House in the 1880s. There she proceeded to organize women's work and clubs. Later in 1884, she married a labor editor and organizer named John O'Sullivan at Boston. They moved into Denison House, a settlement house where O'Sullivan continued to perform labor organizing. This was a unique opportunity for her as it was uncommon for husbands to support their wives working. Together they had 3 children. In 1903 in what may be her greatest achievement, O'Sullivan would become a founder of the Women's Trade Union League. She worked with the union in many reform actions. She also aided the Industrial Workers of the World during the Lawrence Textile Strike. She ultimately ended her career in labor as an inspector for the Massachusetts Board of Labor and Industries, a position she held for 20 years. Early life Mary Kenney was born in Hannibal, Missouri to Irish immigrants. She achieved only a fourth grade education but went on to apprentice as a dressmaker. She spent a two-year period dressmaking with no pay. Post-dressmaking O'Sullivan learned the bindery trade and became an accomplished book binder. It was this experience, and her early work in bookbinding that led her to understand the need for unionization. Working to support her mother, O'Sullivan moved to Chicago in 1888. There she continued her bindery career, but to garner support for herself and other women like her she joined Ladies Federal Local Union Number 2703 and started her union organization, Woman's Bookbinding Union Number 1. While organizing women's labor she lived in Hull House. Upon meeting and getting to know Jane Addams she gained permission to hold union meetings at the house. Eventually she would establish