The correct answer is literacy tests.
The Immigration Restriction League was an organization created in 1894 by three former Harvard alumni. It was anti-immigration and based on the belief that many immigrants, especially from Southern and Eastern Europe, were racially inferior to Anglo-Saxons. The immigrants were seen an the main cause for poverty, low wages, crime and drug problems in the USA.
The IRL pushed for screening of immigrants so that only the literate ones would be allowed entry into the country. Potential immigrants would have to be able to read their own language and the required number of words to be read to be considered literate was 40.
