As host to more immigrants than any other country, the United States has been shaped and reshaped by immigration over the centuries demographically, economically, culturally, socially, and politically. Newcomers have driven fundamental U.S. transformations during four peak periods of significant immigration: establishment of the British colonies, westward expansion and the shift to an agricultural economy in the 19th century, the rise of cities and manufacturing at the turn of the 20th century, and the recent dominance of a services- and knowledge-based economy beginning in the 1970s and continuing today.
The country’s present-day immigration framework was mostly constructed in the 1950s and 1960s, and the last major legislative reforms occurred in 1996. Since then, immigration has become a partisan wedge issue within Congress and the country, with fights chiefly concentrated on the fate of the estimated 11 million unauthorized immigrants in the United States, one of the largest such populations in the world, and enforcement measures at the U.S.-Mexico border. In the face of serious roadblocks to changing immigration laws, recent presidential administrations have increasingly governed through executive action, which has allowed them each to put their mark on the system—at least temporarily.
Although the foundational tenets of the immigration system have remained mostly unchanged over the past several decades, the immigrant population has grown significantly. As of 2019, 44.9 million immigrants lived in the United States—more than double the 1990 number—representing nearly 14 percent of the country’s total population, the highest share since 1910. Immigrant origins are also shifting, with recent arrivals from China and India outpacing those from Mexico, and the overall number of Mexican immigrants declining since 2010. And after peaking at an estimated 12.3 million in 2007, the unauthorized immigrant population has decreased and mostly leveled out around 11 million.
As a result of these shifts, anxieties that have traditionally accompanied sizeable demographic changes, post-9/11 policies that rooted immigration in a new national security narrative, and other factors, immigration has become central to U.S. political debates, helping to propel leaders with ardent but strongly diverging views on the issue. Attempts at major legislative reform have crumbled in the face of such increasing partisanship. This article covers the history of immigration to the United States, provides data on the size and characteristics of the present-day immigrant population, and reviews prospects for future developments.
How Has the Approach to Immigration Changed Throughout U.S. History?
Prior to 1880, immigration to the United States was primarily European, driven by forces including religious and political persecution, crop failure, and the expanding frontiers of the American West and the U.S. industrial revolution. Arrivals of enslaved people from Africa and the Caribbean were high throughout the 18th century but declined dramatically after 1810 and ended in 1861. Chinese immigrants began to arrive in large numbers after gold was discovered in California in 1848.
It was only in 1875 that the U.S. government began to restrict immigration; until that time, virtually all arrivals were admitted. The Immigration Act of 1875 (also known as the Page Act) barred the admission of criminals and made it a felony to import Asian forced laborers and Chinese women. The 1882 Immigration Act further prohibited entry of anyone deemed a “convict, lunatic, idiot, or person unable to take care of himself or herself without becoming a public charge,” and set a fee for arriving noncitizens that would be used to regulate immigration. As the gold rush ended, animosity toward Chinese laborers and other immigrants surged, leading to a further series of racially restrictive immigration laws. The Chinese Exclusion Act of 1882 halted immigration of Chinese laborers for ten years, barred Chinese naturalization, and provided for the deportation of unauthorized Chinese immigrants. Follow-on laws in 1888 and 1892 further restricted immigration from China.
Between 1880 and 1930, more than 27 million immigrants arrived, mainly from Europe and Canada. This peak immigration period—the last major wave prior to the current era—also led to new restrictions. Among them was the 1917 Immigration Act, which prohibited immigration from a newly drawn “Asiatic barred zone” covering most of South and Southeast Asia and nearly the entire Middle East, as well as other groups of migrants such as those who could not pass a literacy test. The Immigration Act of 1924 (also known as the Johnson-Reed Act) established the national-origins quota system, which set a ceiling on the number of immigrants allowed from each country, highly preferencing those from Northern and Western Europe. The 1924 law included no provisions for immigration from South and Central America or Mexico.
The Creation of the Modern U.S. Immigration System
Two decades later, the tides slowly started to turn. In 1943, the Chinese Exclusion Act was repealed after more than 60 years. The 1952 Immigration and Nationality Act continued the national-origins quota system but for the first time allocated a quota for Asian countries. A new philosophy guiding immigration eventually took hold as part the nation’s civil-rights movement, and the resulting Immigration and Nationality Act Amendments of 1965 (the Hart-Cellar Act) repealed the national-origins quota system and replaced it with a seven-category preference system based primarily on family unification. By ending strong preferences for European migration and increasing numerical limits on immigration, the landmark 1965 law set in motion powerful forces that still shape the United States today. Immigration flows that had long been dominated by Europeans gave way to predominantly Latin American and Asian immigration.
