The Women's Trade Union League of New York was one of the three original locals leagues established in the months following the formation of the National Women's Trade Union League (WTUL) in 1903. It was formally organized in February 1904. The WTUL of New York was founded by William English Walling and Mary Kenney O'Sullivan, who worked to recruit Margaret and Mary Dreier, Leonora O'Reilly, Pauline Newman, Clara Lemlich, Alice Bean, and Hilda Svenson, among others. The League served as a kind of training ground for the working women, many of whom had careers later in the labor movement and government service. From 1904 to 1914, the League formed several dozen small shop unions of women in various branches on the clothing industry and provided them with organizational and financial assistance until they could affiliate with the International Ladies' Garment Workers Union or the United Garment workers. The League also reached out and unionized other unorganized women workers throughout its first ten years.
By 1915, the League began to shift their focus away from organization and toward increasing emphasis upon legislation as a way to ameliorate women's working conditions. In the 1920s and 1930s, under the presidencies of Maud Swartz and Rose Schneiderman, they campaigned for for maximum hour and minimum wage laws, which were unsuccessful. Often,the local unions that they originally organized did not take over the financial burden of supporting the League, which led to a loss of resources and funds. By World War II, the League was severely restricted by lack of funds and membership. Gerel Rubien took over as president when Rose Schneiderman retired in 1949 and continued until 1955, five years after the national WTUL disbanded.