• The Naturalization Act of 1790 established the rules for naturalized citizenship, as per Article 1, Section 8 of the Constitution.
• The Chinese Exclusion Act of 1882 was the first (and only) explicitly race-based immigration act.
• The Act of 1891 established a Commissioner of Immigration in the Treasury Department.
• The Emergency Quota Act of 1921 established national quotas on immigration based on the number of foreign-born residents of each nationality who were living in the United States as of the 1910 census.
• The Immigration Act of 1924 aimed at freezing the current ethnic distribution in response to rising immigration from Southern and Eastern Europe, as well as Asia.
• The National Origins Formula was established with the Immigration act of 1924. Total annual immigration was capped at 150,000. Immigrants fit into two categories: those from quota-nations and those from non-quota nations. Immigrant visas from quota-nations were restricted to the same ratio of residents from the country of origin out of 150,000 as the ratio of foreign-born nationals in the United States. The percentage out of 150,000 was the relative number of visas a particular nation received. Non-quota nations, notably those contiguous to the United States only had to prove an immigrant's residence in that country of origin for at least two years prior to emigration to the U.S. Laborers from Asiatic nations were excluded but exceptions existed for professionals, clergy and students to obtain visas.
• The Chinese Exclusion Repeal Act of 1943 repealed the Chinese Exclusion Act and permitted Chinese nationals already in the country to become naturalized citizens.
• The Immigration and Nationality Act of 1952 (or McCarran-Walter Act) somewhat liberalized immigration from Asia, but increased the power of the government to deport illegal immigrants suspected of Communist sympathies.
• Operation Wetback was a 1954 project of the United States Immigration and Naturalization Service (INS) to remove about 1.2 million illegal immigrants from the southwestern United States, with a focus on Mexican nationals. Since the 1920's, the term "wetback" has been a slur referring to Mexicans in general.
• The Immigration and Nationality Act of 1965 discontinued quotas based on national origin, while preference given to those who have U.S. relatives. For the first time Mexican immigration was restricted.
• The Immigration Reform and Control Act of 1986 granted amnesty to illegal immigrants who had been in the United States before 1982 but made it a crime to hire an illegal immigrant.
• The Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRaIRA) made drastic changes to asylum law, immigration detention, criminal-based immigration, and many forms of immigration relief.
• The Real ID Act of 2005 created more restrictions on political asylum, severely curtailed habeas corpus relief for immigrants, increased immigration enforcement mechanisms, altered judicial review, and imposed federal restrictions on the issuance of state driver's licenses to immigrants and others.

  Proposed

  Senate

• Secure America and Orderly Immigration Act (2005)
• Comprehensive Immigration Reform Act of 2006
• Comprehensive Immigration Reform Act of 2007

House