The 1921 Emerging Qiota Act and the 1924 National Origins Act set numerical limits on immigration based on Mnational origin’，making it easy for those of North European background to enter the US，restricting those of South and East European background and excluding Asians. The 1924 Act took effect in 1929 and remained valid until 1965.

Post-World War Two changes Immigration Act of 1965 represented a marked shift of policy. It did away with the national origins system and based immigration permits on the need for occupational skills. Moreover, it placed a high priority on family reunification and established a scvcn-category preference system for family members, skill-based individuals and refugees. It removed the barriers to Asian immigration, which resulted in an unexpectedly greater proportion of immigrants arriving from Asian than from Europe.

1980 and beyond The following pieces of legislation since 1980 have shaped the current immigration system.

Refugee Act of 1980 established a new refugee policy and removed refugees from a world limit of 270,000 annually.

Immigration Reform and Control Act cf 1986 introduced the concept of employer sanctions against companies that “knowingly" hired illegal aliens. It also provided amnesty for many undocumented immigrants. The legacy of this amnesty is sdll felt today, as many of the affected immigrants are becoming citizens and sponsoring their spouses and minor children for immigration.

Immigration Act of 1990 increased the number of employment - based immigrants while also promoting femily immigration. There was an increase in employment-based visas from the previous ceiling of 54,000 to 140,000 annually. The law increased the abilities of employers to bring in immigrants with skills such as science and engineering.

Illegal Immigration Act of 1996 increased border control. The welfare reform legislation of 1996 added another assault by making most legally admitted immigrants ineligible for Temporary Assistance to Needy Families (TANF) and food stamps unless they become citizens. Most newly arrived immigrants are also barred from the Supplemental Security Income (SSI) program.