1791

Naturalization Act restricts citizenship to "free white persons" who reside in the United States for five years and renounce their allegiance to their former country. 

1798

The Alien and Sedition Acts permits the president to deport any foreigner deemed to be dangerous. A revised Naturalization Act imposes a 14-year residency requirement for prospective citizens.

1802

Congress reduces the residency requirement for citizenship to five years.

1808

The importation of slaves into the United States is prohibited.

1848

Treaty of Guadalupe Hidalgo, concluding the Mexican War, extends citizenship to approximately 80,000 Mexican residents of the Southwest. 

1850s

Know Nothing political party unsuccessfully seeks to increase restrictions on naturalization. 

1848

Oregon Territory established, which includes the land that later comprised Washington state.

1850

Bounty Land Act continues a tradition of compensating service in the military with land grants. This act benefits those who participated in the war against Mexico, granting 80 or 160 acres to soldiers who served four to nine months, or to veterans of wars since 1790 that had not previously received a land grant.

1857

U.S. Supreme Court rules in Dred Scott v. Sanford that all blacks (slave and free) were not, nor ever could be, citizens of the United States.

1870

Naturalization Act limits American citizenship to "white persons and persons of African descent," barring Asians from U.S. citizenship. 

1882

Chinese Exclusion Act restricts Chinese immigration. Immigration Act of 1882 levies a tax of 50 cents per immigrant and makes several categories of immigrants ineligible to enter the U.S., including "lunatics" and people likely to become public charges.

1891

Congress makes polygamists, "persons suffering from a loathsome or a dangerous contagious disease," and those convicted of "a misdemeanor involving moral turpitude" ineligible for immigration. The act establishes the Bureau of Immigration within the Treasury Department.

1892

Ellis Island opens; serves as processing center for 12 million immigrants over the next 30 years. 

1901

After President William McKinley is assassinated by a Polish anarchist, Congress enacts the Anarchist Exclusion Act, which allows immigrants to be excluded on the basis of their political opinions. 

1907

Expatriation Act declares that an American woman who marries a foreign national loses her citizenship. Under the Gentleman's Agreement with Japan, the United States agrees not to restrict Japanese immigration in exchange for Japan's promise not to issue passports to Japanese laborers for travel to the continental United States. Japanese laborer are permitted to go to Hawaii, but are barred by executive order from migrating from Hawaii to the mainland. 

1913

California's Alien Land Law prohibits "aliens ineligible for citizenship" (Chinese and Japanese) from owning property in the state. It provides the model for Similar acts in other states. 

1917

Congress enacts a literacy requirement for immigrants over President Woodrow Wilson's veto. The law requires immigrants to be able to read 40 words in some language. The law also specifies that immigration is prohibited from Asia, except from Japan and the Philippines.

1921

Quota Act limits annual European immigration to 3 percent of the number of a nationality group in the U.S. in 1910.

1922

Cable Act partially repeals the Expatriation Act, but declares that an American woman who marries an Asian still loses her citizenship. 

1923

In the landmark case of United States v. Bhaghat Singh Thind, the Supreme Court rules that Indians from the Asian subcontinent could not become naturalized U.S. citizens. 

1924

The Johnson-Reed Act limits annual European immigration to 2 percent of the number of nationality group in the U.S. in 1890. Indian Citizenship Act of 1924 grants citizenship to all Native Americans born in the U.S. Formerly some Indians had acquired citizenship by marrying white men, through military service, by receipt of allotments, or through special treaties or special statutes. But many were still not citizens, and they were barred from the ordinary processes of naturalization open to foreigners. Oriental Exclusion Act prohibits most immigration from Asia, including foreign-born wives and children of U.S. citizens of Chinese ancestry. 

1934

The Tydings-McDuffie Act, which provided for independence for the Philippines on July 4, 1946, strips Filipinos of their status as U.S. nationals and severely restricted Filipino immigration by establishing an annual immigration quota of 50. 

1940

The Alien Registration Act requires the registration and fingerprinting of all aliens in the U.S. over the age of 14. The act classifies Korean immigrants as subjects of Japan. 

1942

Filipinos are reclassified as U.S. citizens, making it possible for them to register for the military. Executive Order 9066 authorizes the military to evacuate 112,000 Japanese Americans from the Pacific coast and placed them in ten internment camps.

1943

The Chinese Exclusion Act is repealed. By the end of the 1940s, all restrictions on Asians acquiring U.S. citizenship are abolished. 

1944

In the case of United States v. Korematsu, the Supreme Court upholds the internment of Japanese Americans as constitutional.

1945

The War Brides Act allows foreign-born wives of U.S. citizens who had served in the U.S. armed forces to enter the U.S.

1946

Fiancés of American soldiers were allowed to enter the U.S. The Luce-Cellar Act extends the right to become naturalized citizens to Filipinos and Asian Indians. The immigration quota is 100 people a year.

1950

The Internal Security Act, passed over President Harry Truman's veto, bars admission to any foreigner who is a Communist or who might engage in activities "which would be prejudicial to the public interest, or would endanger the welfare or safety of the United States." 

1952

McCarran Walter Immigration Act, passed over President Harry Truman's veto, affirms the national-origins quota system of 1924 and limits total annual immigration to one-sixth of one percent of the population of the continental U.S. in 1920. The act exempts spouses and children of U.S. citizens and people born in the Western Hemisphere from the quota.

1965

Immigration and Nationality Act repeals the national origins quota system and gives priority to family reunification. 

1980

The Refugee Act, enacted in response to the boat people fleeing Vietnam, grants asylum to politically oppressed refugees. The Personal Responsibility and Work Opportunity Act, Congress makes citizenship a condition of eligibility for public benefits for most immigrants.