Catt was active in anti-war causes during the 1920s and 1930s. Upon the outbreak of World War I in 1915, a group of women pacifists in the United States began talking about the need to form an organization to help bring the conflict to an end. On January 10, 1915, more than 3,000 women attended a meeting at the Willard Hotel in Washington, DC called by Catt and fellow suffragist Jane Addams. They formed the Women's Peace Party, with Addams elected as chairman and Catt as honorary chairman.