The restriction of Asian immigration to the United States, which began with the Chinese Exclusion Act of 1882, had a significant impact on Mexican immigration to the United States. The exclusion and limitation of Asian immigrants by the United States law created a demand for cheap, unskilled labor in the American labor markets, especially in Hawaii and the West Coast. This demand was met by Mexican immigrants, who were pushed northward mostly by poverty and unemployment in their home country.
The Immigration Act of 1917, also known as the Literacy Act or the Asiatic Barred Zone Act, further restricted Asian immigration by imposing literacy tests on immigrants, creating new categories of inadmissible persons, and barring immigration from the Asia-Pacific zone. This act also affected Mexican immigration, as it imposed a head tax of $8 on each immigrant and excluded those over 16 years old who could not read. However, the act also exempted Mexicans from the literacy test and the Asiatic barred zone, as they were considered "non-immigrants" who entered the United States for temporary work. This exemption was a result of the pressure from American employers and the Mexican government, who wanted to maintain the flow of cheap labor across the border.
Therefore, the restriction of Asian immigration to the United States had a dual effect on Mexican immigration: it increased the demand for Mexican workers in some sectors of the American economy, but it also increased the discrimination and exploitation that they faced as "non-immigrants" who were subject to deportation and exclusion from citizenship.