During WWI, hundreds of thousands of European Jews were uprooted and impoverished, supporting Zionist claims that a Jewish refuge was urgently needed. At the close of the war, the British Balfour Declaration of 1917 gave official sanction to the establishment in Palestine of a national home for the Jewish people. Buoyed by these developments, American Zionism experienced significant growth. Labor Zionism was especially popular in Chicago. It advocated the building of a secular socialist state in Palestine, and included in its orbit the Poalei Zion, Chicago’s Pioneer Women, Habonim youth group, and a large network of secular Jewish supplementary schools including the Workmen’s Circle and Shalom Aleichem schools.