During the 1960s, immigration policy in the United States underwent large changes. Previously, immigration to the United States was dictated by a quota system that heavily favored people from Northern and Western Europe. However, the civil rights movement signaled cultural shifts towards a more diverse society. This led to a serious push to reform the system of immigration in the country.

In 1965, Congress passed the Hart-Celler Act, also known as the Immigration Act of 1965. This legislation did away with the old system which organized immigration around quotas based on national origin. The Hart-Celler Act created seven categories under which prospective immigrants could apply. This allowed people to come to the United States on the basis of having a particular professional skill or previously-established familial connection in the country.

As a result of this policy change, the United States became vastly more diverse. Prior to the 1960s, the great majority of immigrants were white Europeans. After 1965, that changed. In the last fifty years, most immigrants came from elsewhere, particularly Latin America and Asia. This has resulted in significant demographic shifts. Hispanics represent the largest growing racial/ethnic minority in the country. Prior to this policy change, White Americans constituted 84 percent of the country's population. Hispanics were 4 percent, and Asians less than 1 percent. As of five years ago, White people made up 62 percent, Hispanics 18 percent, and Asians 6 percent. The Hart-Celler Act is largely credited for this shift.