gave them a migration quota. Other migrant groups were limited in number by the National Origins quota system, which designated national quotas based on census ratios from 1890. These ratios heavily favored Western European nations and older migrant groups, such as the English, Irish, and Germans. The ratios attempted to limit the rising number of Southern and Eastern European immigrants. The National Origins quota system provided limited family reunification as a means for chain migration and placed a preference on naturalization. If an immigrant became a U.S. citizen, he or she had the ability to obtain non-quota visas for more family members, but as a resident that number was capped annually. Additionally, the Immigration Act of 1924 formally opened the door to chain migration from the entire western hemisphere, placing that group under non-quota status. The abolition of the National Origins quota system came with the Hart–Celler Act of 1965. This legislation placed a heavy emphasis on family reunification, designating 74% of visas for that purpose. There was no limit on spouses, unmarried minor children, and parents of U.S. citizens. The percentages for family reunification were as follows: Unmarried adult children of U.S. citizens (20%), spouses and unmarried children of permanent residents aliens (20%), married children of U.S. citizens (10%), brothers and sisters of U.S. citizens over age 21 (24%). These new visa preferences created a swell of new chain migration and immigration in general. The Third World began to outpace European immigration to America for the first time in history, surpassing it by the end of the 1960s and doubling the numbers of European migration by the end of the 1970s. In reaction to the flood of new immigrants brought by the Hart–Celler Act, and increasing numbers of undocumented immigrants from Mexico and Latin America, Congress attempted to reverse the consequences of the 1965 legislation by enforcing border patrol, using amnesty for undocumented immigrants in the Immigration Reform and Control Act of 1986, and proposing limits to family reunification policies. The effects of ending the Bracero Program were increased undocumented Mexican migration because of the social capital gained during that period. Chain migration had provided relatively easy access to migration for Mexicans that the immigration legislation of the 1980s to the present has attempted to deal with. After 1965 In the United States, the term 'chain migration' is used by advocates of limiting immigration, to partially explain the volume