Lesson 25: Immigration and the Remaking of America Since 1965

For four decades, American immigration law favoured migrants from northern and western Europe. The Immigration and Nationality Act of 1965 — often called the Hart-Celler Act — abolished the national-origins quota system and replaced it with preferences for family reunification and for workers with needed skills, subject to overall caps. Its sponsors did not predict a large change in who came to America. In fact, the law, together with later legislation and world events, transformed the origins of American immigration — and with them, American cities, workplaces, schools and politics.

The 1965 Act and its surprises

The national-origins system, in place since the 1920s, had assigned tiny quotas to most of Asia and Africa and larger ones to northern and western Europe. The 1965 Act ended that system, set an overall ceiling for the Eastern Hemisphere, and gave first preference to close relatives of American citizens and residents. Family reunification then became the main channel of legal immigration: a new immigrant could sponsor relatives, who could in turn sponsor others. That chain effect, combined with refugee crises and the demand for labour, meant that by the 1980s and 1990s the largest flows came from Mexico, Central America, the Caribbean, China, India, the Philippines, Korea and Vietnam, rather than from Europe.

Census figures show the scale of change. The foreign-born share of the American population fell to about 4.7 per cent in 1970, then rose to about 13 per cent by 2010 and roughly 14 per cent in the early 2020s, according to the Census Bureau and the Migration Policy Institute. The absolute number of foreign-born residents rose from under 10 million in 1970 to more than 45 million by the early 2020s. These are counts of people born abroad living in the United States, including naturalised citizens, and they do not by themselves measure unauthorised immigration, which is estimated separately and with greater uncertainty.

Refugees, reform and enforcement

Several later laws shaped the post-1965 story. The Refugee Act of 1980 created a formal asylum and refugee system, used by people fleeing war in Southeast Asia, Central America and later other regions. In 1980 about 125,000 Cubans arrived in the Mariel boatlift. The Immigration Reform and Control Act of 1986 offered legal status to many people who had lived in the United States without authorisation since before 1982, while also penalising employers who knowingly hired unauthorised workers — a combination whose enforcement proved uneven. The Immigration Act of 1990 raised legal immigration levels and created new employment-based categories.

Unauthorised immigration grew from the 1990s, much of it from Mexico, and enforcement expanded in parallel: border patrol staffing, detention and deportations all rose under presidents of both parties. In 2012, President Obama created Deferred Action for Childhood Arrivals (DACA) by executive action, deferring deportation for many people brought to the United States as children. DACA was an executive policy, not a statute, and its legal status has been litigated ever since — a fact that matters for understanding why it has remained contested.

Effects and debates

Economists debate immigration's effects on wages and public budgets, and the findings depend heavily on which workers, periods and places are studied. What is well documented is the demographic and cultural change: by the 2020s, roughly one in four American children lived with at least one immigrant parent, and cities such as Los Angeles, New York, Houston and Miami had large foreign-born populations that reshaped food, language, faith and neighbourhood life. Politically, immigration became one of the sharpest dividing issues in American elections, with disagreement over border enforcement, pathways to citizenship, and the treatment of asylum seekers.

Why it matters

Post-1965 immigration shows how a law can transform a country in ways its authors did not foresee — through family networks, world events and labour markets as much as through the statute's own text.