The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
The role that racism played in immigration policy and procedures during the late 1800s and early 1900s was key in the creation of laws and legislation that limited the entrance of new immigrants to the United States.
For instance, we have the case of the Chinese Exclusion Act of May 6, 1882. that was created to prohibit the immigration of Chinese people that wanted to enter the United States to find work opportunities to improve the living conditions of their families.
It was a time in the United States where American white people thought that these immigrants just came to take what they deserved, that those jobs were theirs, that America was their country and did not belong to anyone; white Americans did not like the idea to mingle with foreigners and rejected foreign culture, language, and traditions.