These Jews became known as rusos, "Russians". In 1889, a group of 824 Russian Jews arrived in Argentina on the S.S. Weser and became gauchos (Argentine cowboys). They bought land and established a colony named Moises ville. In dire economic straits, they appealed to the German Jewish philanthropist Baron Maurice de Hirsch, who founded the Jewish Colonization Association. In its heyday, the Association owned more than 600,000 hectares of land. Between 1906 and 1912, some 13,000 Jews immigrated to Argentina every year, mostly from Europe, but also from Morocco and the Ottoman Empire. By 1920, more than 150,000 Jews were living in Argentina. After the death of his son and heir, de Hirsch devoted himself to Jewish philanthropy and alleviating Jewish suffering in Eastern Europe. He developed a plan to bring Jews to Argentina as autonomous agricultural settlers. This meshed with Argentina's campaign to attract immigrants. The 1853 constitution guaranteed religious freedom, and the country had vast, unpopulated land reserves. Under President Domingo F. Sarmiento, a policy of mass immigration was encouraged; it provided relief to refugees fleeing the violent pogroms in the Russian Empire in 1881. Jewish agricultural settlements were established in the provinces of Buenos Aires (Lapin, Rivera), Entre Ríos (San Gregorio, Villa Domínguez, Carmel, Ingeniero Sajaroff, Villa Clara, and Villaguay), and Santa Fe (Moisés Ville). The national census of 1895 recorded that, of the 6,085 people who identified as Jewish, 3,880 (about 64%) lived in Entre Ríos. Despite antisemitism and increasing xenophobia, Jews became involved in most sectors of Argentine society. Many settled in cities, especially Buenos Aires. As they were prohibited from positions in the government or military, many became farmers, peddlers, artisans, and shopkeepers. 20th century World War II and antisemitism Argentina kept its doors open to Jewish immigration until 1938, when Adolf Hitler and the Nazis in Germany began to take more actions against Jews, and tensions rose across Europe in preparation for war. The government imposed new regulations on immigration; it was severely curtailed at a time of increasing persecution of Jews and the outbreak of World War II, when Jews sought a safe haven from the Nazis. Six million Jews died in Europe during the Holocaust. Juan Domingo Perón's rise to power in 1946 in Argentina after the war worried many Jews in the country. As Minister of War, he had signed Argentina's declaration of war against the Axis Powers, but as