Italian migration to Australia increased markedly only after heavy restrictions were placed on Italians' entry to the United States. More than two million Italian migrants entered the United States from the start of the 20th century to the outbreak of the First World War, whereas only about twelve thousand Italians had entered Australia in the same period. In 1917, while war was still on, the United States introduced a Literacy Act to curtail its immigration flow—which had reached a high number in the years immediately before the war—and Canada enacted similar legislation two years later. In 1921, United States policy became even stricter, with the establishment of a quota system that limited the total intake of Italian immigrants in any one year to about 41,000 (calculated as 3% of the number of Italians residing in the United States in 1910). Furthermore, in 1924, the figures related to the entry of Italians were cut almost to zero, as they were meant to represent the 2% of the Italian component in the United States in 1890.