Historical events: Major historical events, such as wars and famines, have also played a role in shaping immigration patterns to the United States. For example, the large influx of Irish immigrants in the mid-19th century was largely due to the Great Famine in Ireland, while the wave of Eastern European immigrants in the late 19th and early 20th centuries was driven in part by political and economic unrest in Europe.
Immigration laws: US immigration laws have also had a significant impact on the composition of the immigrant population. For example, the Chinese Exclusion Act of 1882 severely restricted Chinese immigration to the United States, while the Immigration Act of 1924 established quotas for immigrants from different countries.
Asylum and refugee status: The United States has also granted asylum and refugee status to individuals fleeing persecution or war in their home countries. For example, the United States accepted large numbers of refugees from the Vietnam War in the 1970s and from the Syrian Civil War in the 2010s.
Today, the United States continues to be a popular destination for immigrants from all over the world. According to the 2020 census, there were over 44.7 million foreign-born people in the United States, making up about 13.5% of the total population. The top countries of origin for immigrants in the United States are Mexico, China, India, the Philippines, and El Salvador.