History of immigration to the United States

Seeking religious freedom in the New World, one hundred English Pilgrims established a small settlement near Plymouth, Massachusetts in 1620. Tens of thousands of English Puritans arrived, mostly from the East Anglian parts of England (Norfolk, Suffolk, Essex), as well as Kent and East Sussex.,[3] and settled in Boston, Massachusetts and adjacent areas from around 1629 to 1640 to create a land dedicated to their religion. The earliest New English colonies, Massachusetts, Connecticut, Rhode Island, and New Hampshire, were established along the northeast coast. Large scale immigration to this region ended before 1700, though a small but steady trickle of later arrivals continued.[4]

The New English colonists were the most urban and educated of all their contemporaries, and they had many skilled farmers, tradesmen and craftsmen among them. They started the first university, Harvard, in 1635 in order to train their ministers. They mostly settled in small villages for mutual support (nearly all of them had their own militias) and common religious activities. Shipbuilding, commerce, agriculture, and fishing were their main sources of income. New England's healthy climate (the cold winters killed the mosquitoes and other disease-bearing insects), small widespread villages (minimizing the spread of disease), and an abundant food supply resulted in the lowest death rate and the highest birth rate of any of the colonies. The Eastern and Northern frontier around the initial New England settlements was mainly settled by the descendants of the original New Englanders. Immigration to the New England colonies after 1640 and the start of the English Civil War decreased to less than 1% (about equal to the death rate) in nearly all of the years prior to 1845. The rapid growth of the New England colonies (approximately 900,000 by 1790) was almost entirely due to the high birth rate (>3%) and the low death rate (<1%) per year.[5]

The Dutch, primarily driven by the United East Indian Company, first established settlements along the Hudson River in New York starting about 1626. Wealthy Dutch patroons set up large landed estates along the Hudson River and brought in farmers who became renters. Others established rich trading posts to trade with Native Americans and started cities such as New Amsterdam (now New York City) and Albany, New York.[6] After the British took over and renamed the colony New York, Germans (from the Palatinate), and Yankees (from New England) began arriving.[7]

Maryland, New York, New Jersey, Pennsylvania, and Delaware formed the middle colonies. Pennsylvania was settled by Quakers from Britain, followed by Ulster Scots (Northern Ireland) on the frontier and numerous German Protestant sects, including the German Palatines. The earlier colony of New Sweden had small settlements on the lower Delaware River, with immigrants of Swedes and Finns. These colonies were absorbed by 1676.[8]

The middle colonies' were scattered West of New York City (established 1626; taken over by the English in 1664) and Philadelphia, Pennsylvania (established 1682). The initial Dutch colony of New York had the most eclectic collection of residents from many different nations and prospered as a major trading and commercial center after about 1700. From around 1680 to 1725, the Pennsylvania colonial center was dominated by the Quakers for decades after they emigrated, mainly from the North Midlands of England. During this time, the main commercial center of Philadelphia was run mostly by prosperous Quakers, supplemented by many small farming and trading communities, with a strong German contingent located in several small towns in the Delaware River valley.[9]

Starting around 1680, when Pennsylvania was founded, many more settlers arrived to the middle colonies. Many Protestant sects were encouraged to settle there for freedom of religion and good, cheap land. Their origins were about 60% British and 33% German. By 1780, New York's population were around 27% descendants of Dutch settlers, about 6% were African, and the remainder were mostly English with a wide mixture of other Europeans. New Jersey, and Delaware had a British majority, with 7–11% German-descendants, about 6% African population, and a small contingent of the Swedish descendants of New Sweden.

The colonial frontier was mainly settled from about 1717 to 1775. These were mostly Presbyterian settlers from North England border lands, Scotland, and Ulster, fleeing hard times and religious persecution.[10] The fourth major center of settlement was the Western frontier, located in the Western parts of Pennsylvania and in the South, which was settled during the early to late 18th century by mostly Scots-Irish, with others mostly from North England border lands. Some French Huguenots and Germans were also present. Between 250,000 and 400,000 Scots-Irish migrated to America in the 18th century.[10] The Scots-Irish soon became the dominant culture of the Appalachians from Pennsylvania to Georgia. Areas where people reported 'American' ancestry were the places where, historically, northern English, Scottish and Scots-Irish Protestants settled: in the interior of the South, and the Appalachian region.[11] Scots-Irish American immigrants, were made up of people from the southernmost counties of Scotland who had initially settled in Ireland. They were heavily Presbyterian, and largely self-sufficient. The Scots-Irish arrived in large numbers during the early 18th century and they often preferred to settle in the back country and the frontier from Pennsylvania to Georgia, where they mingled with second generation and later English settlers. They enjoyed the very cheap land and independence from established governments common to frontier settlements. Often, the main port of entry for these immigrants was Philadelphia, after which they (or, in many cases, their descendants) migrated west and south.

The mostly agricultural Southern English colonies initially had very high death rates for new settlers due to malaria, yellow fever, and other diseases as well as skirmishes with Native Americans. Despite this, a steady flow of new immigrants, mostly from Central England and the London area, kept up population growth. As early as 1630, initial areas of settlement had been largely cleared of Native Americans by major outbreaks of measles, smallpox, and bubonic plague beginning already decades before European settlers began arriving in large numbers. The leading killer was smallpox, which arrived in the New World around 1510–1530.[12]

Initially, the plantations established in these colonies were mostly owned by friends (mostly minor aristocrats and gentry) of the British-appointed governors. A group of Gaelic-speaking Scottish Highlanders created a settlement at Cape Fear in North Carolina, which remained culturally distinct until the mid-18th century, at which point it was swallowed up by the dominant English-origin culture.[13] Many settlers from Europe arrived as indentured servants, having had their passage paid for, in return for five to seven years of work, including free room and board, clothing, and training, but without cash wages. After their periods of indenture expired, many of these former servants founded small farms on the frontier.

By the early 18th century, the involuntary migration of African slaves was a significant component of the immigrant population in the southern colonies. Between 1700 and 1740 a large majority of the net overseas migration to these colonies were Africans. In the third quarter of the 18th century, the population of that region amounted to roughly 55% British, 38% Black, and 7% German. In 1790 42% of the population in South Carolina and Georgia was of African origin.[14] Before 1800 the growing of tobacco, rice and indigo in plantations in the southern colonies relied heavily on the labor of slaves from Africa.[15] The Atlantic slave trade to mainland North America declined after 1775 and was outlawed in the United States by the 1808 Act Prohibiting Importation of Slaves, although some slaves continued to be smuggled in.

While the thirteen colonies differed in how they were settled and by whom, they had many similarities. Nearly all were settled and financed by privately organized British settlers or families using free enterprise without any significant Royal or Parliamentary government support. Nearly all commercial activity comprised small, privately owned businesses with good credit both in America and in England, which was essential since they were often cash poor. Most settlements were largely independent of British trade since they grew or manufactured nearly everything they needed; the average cost of imports per household was 5–15 pounds sterling per year. Most settlements consisted of complete family groups with several generations present. The population was rural, with close to 80% owning the land they lived and farmed on. After 1700, as the Industrial Revolution progressed, more of the population started to move to cities, as had happened in Britain. Initially, the Dutch and German settlers spoke languages brought over from Europe, but English was the main language of commerce. Governments and laws mainly copied English models. The only major British institution to be abandoned was the aristocracy, which was almost totally absent. The settlers generally established their own law-courts and popularly elected governments. This self-ruling pattern became so ingrained that for the next 200 years almost all new settlements had their own government up and running shortly after arrival.

After the colonies were established their population growth comprised almost entirely organic growth with foreign-born immigrant populations rarely exceeding 10%. The last significant colonies to be settled primarily by immigrants were Pennsylvania (post-1680s), the Carolinas (post-1663), and Georgia (post-1732). Even here the immigrants came mostly from England and Scotland with the exception of Pennsylvania, with a large Germanic contingent. Elsewhere internal American migration from other colonies provided nearly all of the settlers for each new colony or state.[16] Populations grew by about 80% over a 20-year period, at a "natural" annual growth rate of 3%.

Over half of all new British immigrants in the South initially arrived as indentured servants,[17] mostly poor young people who could not find work in England nor afford passage to America. In addition in the 18th century about 60,000 British convicts guilty of minor offences were transported to the British colonies, the "serious" criminals having in general been executed. Ironically, these convicts are often the only immigrants with nearly complete immigration records as other immigrants typically arrived with few or no records.[18]

Although Spain set up a few forts in Florida, notably San Agustín (present-day Saint Augustine) in 1565, they sent few settlers to Florida. Spaniards moving north from Mexico founded the San Juan on the Rio Grande in 1598, and Santa Fe in 1607–1608. The settlers were forced to leave temporarily for 12 years (1680–1692) by the Pueblo Revolt before returning.

Spanish Texas lasted from 1690 to 1821 when Texas was governed as a colony which was separate from New Spain. In 1731, Canary Islanders (or "Isleños") arrived to establish San Antonio.[19] The majority of the few hundred Texan and New Mexican colonizers in the Spanish colonial period were Spaniards and criollos.[20] California, New Mexico, and Arizona all had Spanish settlements. In 1781 Spanish settlers founded Los Angeles.

At the time they joined the U.S., Californios in California numbered about 10,000 and Tejanos in Texas about 4,000. New Mexico had 47,000 Spanish settlers in 1842. Arizona was only thinly settled.

However, not all these settlers were of European descent. As in the rest of the American colonies, new settlements were based on the casta system, and although all could speak Spanish, it was a melting pot of whites, Natives, and mestizos.

In the late 17th century, French expeditions established a foothold on the Saint Lawrence River, Mississippi River, and Gulf Coast. Interior trading posts, forts, and cities were thinly spread throughout Louisiana such as Saint Louis, Baton Rouge, Sault Sainte Marie, Prairie du Rocher, and Sainte-Geneviève. The city of Detroit was the third largest settlement in New France. New Orleans expanded when several thousand French-speaking refugees from the region of Acadia (now Nova Scotia, Canada) made their way to Louisiana following British expulsion, settling largely in the Southwest Louisiana region now called Acadiana. Their descendants are now called Cajun and still dominate the coastal areas.[21] It is estimated that 7,000 European immigrants settled in Louisiana during the 18th century.

Between 1850 and 1930, about 5 million Germans migrated to the United States, peaking between 1881 and 1885 when a million Germans settled primarily in the Midwest. Between 1820 and 1930, 3.5 million British and 4.5 million Irish entered America. Before 1845 most Irish immigrants were Protestants. After 1845, Irish Catholics began arriving in large numbers, largely driven by the Great Famine.[30]

After 1880 larger steam-powered oceangoing ships replaced sailing ships, which resulted in lower fares and greater immigrant mobility. In addition, the expansion of a railroad system in Europe made it easier for people to reach oceanic ports to board ships. Meanwhile, farming improvements in Southern Europe and the Russian Empire created surplus labor. Young people between the ages of 15 to 30 were predominant among newcomers. This wave of migration, constituting the third episode in the history of U.S. immigration, may be better referred to as a flood of immigrants, as nearly 25 million Europeans made the long trip. Italians, Greeks, Hungarians, Poles, and others speaking Slavic languages made up the bulk of this migration. 2.5 to 4 million Jews were among them.

Each group evinced a distinctive migration pattern in terms of the gender balance within the migratory pool, the permanence of their migration, their literacy rates, the balance between adults and children, and the like. But they shared one overarching characteristic: they flocked to urban destinations and made up the bulk of the U.S. industrial labor pool, making possible the emergence of such industries as steel, coal, automotive, textile, and garment production, enabling the United States to leap into the front ranks of the world's economic giants.

Their urban destinations, numbers, and perhaps an antipathy towards foreigners, led to the emergence of the second wave of organized xenophobia. By the 1890s, many Americans, particularly from the ranks of the well-off, white, and native-born, considered immigration to pose a serious danger to the nation's health and security. In 1893 a group formed the Immigration Restriction League, and it, along with other similarly inclined organizations, began to press Congress for severe curtailment of foreign immigration.

Irish and German Catholic immigration was opposed in the 1850s by the Nativist/Know Nothing movement, originating in New York in 1843 as the American Republican Party (not to be confused with the modern Republican Party). It was empowered by popular fears that the country was being overwhelmed by Catholic immigrants, who were often regarded as hostile to American values and controlled by the Pope in Rome. Active mainly from 1854–56, it strove to curb immigration and naturalization, though its efforts met with little success. There were few prominent leaders, and the largely middle-class and Protestant membership fragmented over the issue of slavery, most often joining the Republican Party by the time of the 1860 presidential election.[31][32]

European immigrants joined the Union Army in large numbers, including 177,000 born in Germany and 144,000 born in Ireland, a full 16% of the Union Army.[33] Many Germans could see the parallels between slavery and serfdom in the old fatherland.[34]

Between 1840 and 1930, about 900,000 French Canadians left Quebec in order to immigrate to the United States and settle, mainly in New England. Considering the fact that the population of Quebec was only 892,061 in 1851, this was a massive exodus. 13.6 million Americans claimed to have French ancestry in the 1980 census. A large portion of them have ancestors who emigrated from French Canada, since immigration from France was low throughout the history of the United States. During the same period, almost 4 million other Canadians immigrated to the U.S. In the New England states 12% of the population can trace its ancestry back to Quebec and 10% can trace its ancestry back to the Maritime Provinces. The communities established by these immigrants became known as Little Canada.

Shortly after the U.S. Civil War, some states started to pass their own immigration laws, which prompted the U.S. Supreme Court to rule in 1875 that immigration was a federal responsibility.[35] In 1875, the nation passed its first immigration law, the Page Act of 1875, also known as the Asian Exclusion Act, outlawing the importation of Asian contract laborers, any Asian woman who would engage in prostitution, and all people considered to be convicts in their own countries.[36]

In 1882 Congress passed the Chinese Exclusion Act. By excluding all Chinese laborers from entering the country, the Chinese Exclusion Act severely curtailed the number of immigrants of Chinese descent allowed into the United States for 10 years.[37] The law was renewed in 1892 and 1902. During this period, Chinese migrants illegally entered the United States through the loosely guarded U.S.-Canadian border.[38]

Illustration from Walter Crane's Columbia's Courtship: A Picture History of the United States in Twelve Emblematic Designs in Color with Accompanying Verses(1893)

Prior to 1890, the individual states, rather than the Federal government, regulated immigration into the United States.[39] The Immigration Act of 1891 established a Commissioner of Immigration in the Treasury Department.[40] The Canadian Agreement of 1894 extended U.S. immigration restrictions to Canadian ports.

Late 19th Century broadside advertisement offering cheap farm land to immigrants; few went to Texas after 1860.

The Dillingham Commission was set up by Congress in 1907 to investigate the effects of immigration on the country. The Commission's 40-volume analysis of immigration during the previous three decades led it to conclude that the major source of immigration had shifted from Central, Northern, and Western Europeans to Southern Europeans and Russians. It was, however, apt to make generalizations about regional groups that were subjective and failed to differentiate between distinct cultural attributes.[41][42]

The 1910s marked the high point of Italian immigration to the United States. Over two million Italians immigrated in those years, with a total of 5.3 million between 1880 and 1920.[43][44] About half returned to Italy, after working an average of five years in the U.S.[45]

About 1.5 million Swedes and Norwegians immigrated to the United States within this period, due to opportunity in America and poverty and religious oppression in united Sweden-Norway. This accounted for around 20% of the total population of the kingdom at that time. They settled mainly in the Midwest, especially Minnesota and the Dakotas. Danes had comparably low immigration rates due to a better economy; after 1900 many Danish immigrants were Mormon converts who moved to Utah.

In this Rosh Hashana greeting card from the early 1900s, Russian Jews, packs in hand, gaze at the American relatives beckoning them to the United States. Over two million Jews fled the pogroms of the Russian Empire to the safety of the U.S. from 1881–1924.

Mulberry Street, along which Manhattan's Little Italy is centered. Lower East Side, circa 1900.

Over two million Central Europeans, mainly Catholics and Jews, immigrated between 1880 and 1924. People of Polish ancestry are the largest Central European ancestry group in the United States after Germans. Immigration of Eastern Orthodox ethnic groups was much lower.

Lebanese and Syrian immigrants started to settle in large numbers in the late 19th and early 20th centuries. The vast majority of the immigrants from Lebanon and Syria were Christians, but smaller numbers of Jews, Muslims, and Druze also settled. Many lived in New York City's Little Syria and in Boston. In the 1920s and 1930s, a large number of these immigrants set out West, with Detroit getting a large number of Middle Eastern immigrants, as well as many Midwestern areas where the Arabs worked as farmers.

Congress passed a literacy requirement in 1917 to curb the influx of low-skilled immigrants from entering the country.

Congress passed the Emergency Quota Act in 1921, followed by the Immigration Act of 1924, which supplanted earlier acts to effectively ban all immigration from Asia and set quotas for the Eastern Hemisphere so that no more than 2% of nationalities as represented in the 1890 census were allowed to immigrate to America.

The Sunday magazine of the New York World appealed to Immigrants with this 1906 cover page celebrating their arrival at Ellis Island.

"New immigration" was a term from the late 1880s that came from the influx of Catholic and Jewish immigrants from southern and eastern Europe (areas that previously sent few immigrants).[46] Though the majority of immigrants came through Ellis Island in New York, thus making the Northeast a major target of settlement, there were various efforts, such as the Galveston Movement, to redirect immigrants to other ports and disperse some of the settlement to other areas of the country.

Nativists feared the new arrivals lacked the political, social, and occupational skills needed to successfully assimilate into American culture. This raised the issue of whether the U.S. was still a "melting pot," or if it had just become a "dumping ground," and many old-stock Americans worried about negative effects on the economy, politics, and culture.[47] A major proposal was to impose a literacy test, whereby applicants had to be able to read and write in their own language before they were admitted.[48]

Catholicism became a leading denomination 1860–1910. St. John Cantius, one of Chicago's "Polish Cathedrals" was one of the churches these new immigrants founded.

This law allowed foreign-born children of American mothers and alien fathers who had entered America before the age of 18 and had lived in America for five years to apply for American citizenship for the first time.[50] It also made the naturalization process quicker for the alien husbands of American wives.[50] This law equalized expatriation, immigration, naturalization, and repatriation between women and men.[50][51] However, it was not applied retroactively, and was modified by later laws, such as the Nationality Act of 1940.[50][52]

In 1934, the Tydings–McDuffie Act provided independence of the Philippines on July 4, 1946. Until 1965, national origin quotas strictly limited immigration from the Philippines. In 1965, after revision of the immigration law, significant Filipino immigration began, totaling 1,728,000 by 2004.[53]

In 1945, the War Brides Act allowed foreign-born wives of U.S. citizens who had served in the U.S. Armed Forces to immigrate to the United States. In 1946, The War Brides Act was extended to include the fiancés of American soldiers. In 1946, the Luce–Celler Act extended the right to become naturalized citizens to those from the newly independent nation of The Philippines and to Asian Indians, the immigration quota being set at 100 people per year per country.[54]

At the end of World War II, "regular" immigration almost immediately increased under the official national origins quota system as refugees from war-torn Europe began immigrating to the U.S. After the war, there were jobs for nearly everyone who wanted one, when most women employed during the war went back into the home. From 1941 to 1950, 1,035,000 people immigrated to the U.S., including 226,000 from Germany, 139,000 from the UK, 171,000 from Canada, 60,000 from Mexico, and 57,000 from Italy.[55]

The Displaced Persons Act of 1948 finally allowed the displaced people of World War II to start immigrating.[56] Some 200,000 Europeans and 17,000 orphans displaced by World War II were initially allowed to immigrate to the United States outside of immigration quotas. President Harry S. Truman signed the first Displaced Persons (DP) act on June 25, 1948, allowing entry for 200,000 DPs, then followed with the more accommodating second DP act on June 16, 1950, allowing entry for another 200,000. This quota, including acceptance of 55,000 Volksdeutschen, required sponsorship for all immigrants. The American program was the most notoriously bureaucratic of all the DP programs and much of the humanitarian effort was undertaken by charitable organizations, such as the Lutheran World Federation as well as other ethnic groups. Along with an additional quota of 200,000 granted in 1953 and more in succeeding years, a total of nearly 600,000 refugees were allowed into the country outside the quota system, second only to Israel's 650,000.

In 1950, after the start of the Korean War, the Internal Security Act barred admission of Communists, who might engage in activities "which would be prejudicial to the public interest, or would endanger the welfare or safety of the United States."

In 1950, the invasion of South Korea by North Korea started the Korean War and left a war-ravaged Korea behind. There was little U.S. immigration due to the national origin quotas of the immigration law. Significant Korean immigration began in 1965 after revision of the law, totaling 848,000 by 2004.

The Immigration and Nationality Act of 1952 affirmed the national-origins quota system of 1924 and limited total annual immigration to one-sixth of one percent of the population of the continental United States in 1920, or 175,455. This exempted the spouses and children of U.S. citizens and people born in the Western Hemisphere from the quota. In 1953, the Refugee Relief Act extended refugee status to non-Europeans.

In 1954, Operation Wetback forced the return of thousands of illegal immigrants to Mexico.[57] Between 1944 and 1954, "the decade of the wetback," the number of illegal immigrants coming from Mexico increased by 6,000 percent. It is estimated that before Operation Wetback got underway, more than a million workers had crossed the Rio Grande illegally. Cheap labor displaced native agricultural workers, and increased violation of labor laws and discrimination encouraged criminality, disease, and illiteracy. According to a study conducted in 1950 by the President's Commission on Migratory Labor in Texas, the Rio Grande Valley cotton growers were paying approximately half of the wages paid elsewhere in Texas. The United States Border Patrol aided by municipal, county, state, federal authorities, and the military, began a quasi-military operation of the search and seizure of all illegal immigrants. Fanning out from the lower Rio Grande Valley, Operation Wetback moved Northward. Initially, illegal immigrants were repatriated through Presidio because the Mexican city across the border, Ojinaga, had rail connections to the interior of Mexico by which workers could be quickly moved on to Durango. The forces used by the government were relatively small, perhaps no more than 700 men, but were augmented by border patrol officials who hoped to scare illegal workers into fleeing back to Mexico. Ships became a preferred mode of transport because they carried illegal workers farther from the border than buses, trucks, or trains. It is difficult to estimate the number of illegal immigrants that left due to the operation—most voluntarily. The INS claimed as many as 1,300,000, though the number officially apprehended did not come anywhere near this total. The program was ultimately abandoned due to questions surrounding the ethics of its implementation. Citizens of Mexican descent complained of police stopping all "Mexican looking" people and utilizing extreme "police-state" methods including deportation of American-born children who were citizens by law.[58]

The failed 1956 Hungarian Revolution, before being crushed by the Soviets, forged a temporary hole in the Iron Curtain that allowed a burst of refugees to escape, with 245,000 Hungarian families being admitted by 1960. From 1950 to 1960, the U.S. had 2,515,000 new immigrants with 477,000 arriving from Germany, 185,000 from Italy, 52,000 from the Netherlands, 203,000 from the UK, 46,000 from Japan, 300,000 from Mexico, and 377,000 from Canada.

The 1959 Cuban revolution led by Fidel Castro drove the upper and middle classes to exile, and 409,000 families immigrated to the U.S. by 1970.[59] This was facilitated by the 1966 Cuban Adjustment Act, which gave permanent resident status to Cubans physically present in the United States for one year if they entered after January 1, 1959.

This all changed with the passage of the Immigration and Nationality Act of 1965, a by-product of the civil rights movement and a jewel in the crown of President Lyndon Johnson's Great Society programs. The measure had not been intended to stimulate immigration from Asia, the Middle East, Africa, and elsewhere in the developing world. Rather, by doing away with the racially-based quota system, its authors had expected that immigrants would come from "traditional" societies such as Italy, Greece, and Portugal places subject to very small quotas in the 1924 Act. The 1965 Act replaced the quotas with preferential categories based on family relationships and job skills, giving particular preference to potential immigrants with relatives in the United States and with occupations deemed critical by the U.S. Department of Labor.

After 1970, however, following an initial influx from European countries, immigrants from places like Korea, China, India, the Philippines, and Pakistan, as well as countries in Africa became more common.

In 1986, the Immigration Reform and Control Act (IRCA) was passed, creating, for the first time, penalties for employers who hired illegal immigrants. IRCA, as proposed in Congress, was projected to give amnesty to about 1,000,000 workers in the country illegally. In practice, amnesty for about 3,000,000 immigrants already in the United States was granted. Most were from Mexico. Legal Mexican immigrant family numbers were 2,198,000 in 1980, 4,289,000 in 1990 (includes IRCA), and 7,841,000 in 2000. Adding another 12,000,000 illegal immigrants of which about 80% are thought to be Mexicans would bring the Mexican family total to over 16,000,000—about 16% of the Mexican population.

Passed in September 1996, the Illegal Immigration Reform and Immigration Responsibility Act (IIRIRA) was a comprehensive immigration reform focused on restructuring the process for admitting or removing undocumented immigrants.[60] Its passing helped to strengthen U.S. immigration laws, restructured immigration law enforcement, and sought to limit immigration by addressing undocumented migration. These reforms affected legal immigrants, those seeking entry into the U.S., and those living undocumented in the U.S.

IIRIRA created new barriers for refugees seeking asylum in the U.S. by narrowing asylum criteria previously established in the Refugee Act of 1980.[61] To prevent fraudulent asylum filings from people who were migrating for economic or work-related reasons, IIRIRA imposed an all-inclusive filing deadline called the "One Year Bar" to asylum.[62] IIRIRA provided limited exceptions to this rule when an "alien demonstrates to the satisfaction of the Attorney General either the existence of changed circumstances which materially affect the applicant's eligibility for asylum or extraordinary circumstances relating to the delay in filing the application."[63] IIRIRA also made the asylum process more difficult for refugees by allowing for the resettlement of refugees to third countries, "precluding appeals" to denied asylum applications, implementing higher processing fees, and having enforcement officers rather than judges determine the expedited removal of refugees.[60]

Law enforcement under IIRIRA was strengthened to restrict unlawful immigration. The Act sought to prevent illegal immigration by expanding the number of Border Patrol agents and allowing the Attorney General to obtain resources from other federal agencies. Provisions were also made to improve infrastructure and barriers along the U.S. border area.[64] IIRIRA also delegated law enforcement capabilities to state and local officers via 287(g) agreements.[64] Illegal entry into the U.S. was made more difficult by cooperation between federal and local law enforcement, in addition to stiffening penalties for illegal entry and racketeering activities which included alien smuggling and document fraud.

IIRIRA addressed unlawful migration already present in the U.S. through enhanced tracking systems that included detecting employment eligibility and visa stay violations as well as creating counterfeit-resistant forms of identification.[65] The Act also established the 3 and 10 year re-entry bars for immigrants who accumulated unlawful presence in the U.S. and become inadmissible upon leaving the country.[66]

The restructuring of law enforcement contributed to an increased number of arrests, detentions, and removals of immigrants.[67] Under IIRIRA, the mandatory detention of broad groups of immigrants occurred, including those who had legal residence status but upon removal could have their status be removed after committing violent crimes. Relief and access to federal services were also redefined for immigrants as IIRIRA reiterated the 1996 Welfare Reform Act's tier system between citizens, legal immigrants, refugees, and illegal immigrants which determined public benefits eligibility.[65] In addition, IIRIRA also redefined financial self-sufficiency guidelines of sponsors who previously did not have to meet an income requirement to sponsor an immigrant.[65]