What were the immigration policies of the 1920s in the United States and were there differences between the western and eastern hemispheres laws? Please provide sources.

 

Starting from 1917, the US began enacting widely restrictive immigration laws; which entailed a literacy test, increase in taxes paid by new immigrants upon arrival etc. By 1920, the government sought a new way to restrict immigration as the literacy rate and increased taxes were not enough to prevent most potential immigration.

Republican Senator William Dillingham thus introduced a measure to create immigration quotas, which were to be set at 3% of the total population of the foreign-born of each nationality in the United States, as recorded in the 1910 census. With this new measure, the total number of visas available each year to new immigrants decreased to only 350,000. However it did not establish quotas of any kind for residents of the Western Hemisphere.

When the congressional debate over immigration began in 1924, it was more about possible adjustments that could be made, rather than the question of whether or not to abolish it. Although there existed a considerable amount of politicians arguing for higher immigration quotas, those who wanted to restrict the measures even more triumphed. The existing quota from 3% to 2% of the foreign-born population. The 1924 Immigration Act also changed the nature of the quota calculations. Instead of only counting the number of people born outside of the US, or the number of immigrants in the country; the new law sought to trace the origins of every US citizen, including natural-borns. The new calculations thus included a considerable amount of British descents, which resulted in an increase in the amount of visas available for individuals from the British Isles and Western Europe increased, but that from everywhere else was restrained.

The Act also prohibited entries of those who were not eligible to obtain citizenship (under the existing laws dating back to 1790 and 1870, excluding people of Asian lineage from naturalizing). The 1924 Act thus entailed that even Asians not previously prevented from immigrating (e.g. the Japanese) would no longer be admitted to the US. 

The most basic purpose of the act is said to be the protection of the ideal U.S. homogeneity. The Congress, by deciding to not take action despite increased tensions with Japan, clearly demonstrated that preserving the ethnic composition of the country was more important than promoting a good relationship with Japan.