(later renamed the Women's Political Union), to recruit working class women into the suffrage movement. The core membership of the league comprised 20,000 factory, laundry, and garment workers from the Lower East Side of New York City. The organization successfully lobbied for an equal pay resolution for New York teachers. Through this group, Blatch organized and led the 1910 New York suffrage parade. Blatch succeeded in mobilizing many working-class women, even as she continued to collaborate with prominent society women. She could organize militant street protests while still working expertly in backroom politics to neutralize the opposition of Tammany Hall politicians who feared the women would vote for prohibition. During her years advocating for women's rights, Blatch also published a book called Mobilizing Woman Power, which inspired women from across the United States to recognize their place in society. The Union achieved significant political strength, and actively lobbied for a New York state constitutional amendment to give women the vote, which was achieved in 1917 after Tammany Hall relaxed its opposition. In 1915, Blatch's Women's Political Union merged with Alice Paul and Lucy Burns' Congressional Union, which eventually became the National Woman's Party. War and postwar During World War I, Blatch devoted her time to the war effort, heading the Woman's Land Army of America, which provided additional farm labor. She wrote Mobilizing Woman Power in 1918, about women's role in the war effort, urging women to "go to work". In 1920, she published A Woman's Point of View, where she took a pacifist position due to the destruction of the war. After the passage of the Nineteenth Amendment in 1920, Blatch joined the National Woman's Party to fight for passage of the Equal Rights Amendment, rather than the protective legislation supported by the Women's Trade Union League. She also joined the Socialist Party, and was nominated for New York City Comptroller and later the New York State Assembly, but did not win office. She eventually left the party, because of its support for protective legislation for women workers. During the 1920s, Blatch also worked on behalf of the League of Nations, proposing improvements for the amendments to the League's Covenant. Last years and death In 1939, Blatch suffered a fractured hip and moved to a nursing home in Greenwich, Connecticut. Her memoir, Challenging Years, was published in 1940 and she died the week before Thanksgiving that same year in