Congress passed the Emergency Quota Act to sharply limit immigration by setting numerical quotas based on national origin. The law used a percentage of each nationality already living in the United States (from an earlier census) to set country limits. This marked the start of a restrictive quota era that strongly shaped transatlantic migration, especially from Southern and Eastern Europe.
The Immigration Act of 1924 (Johnson–Reed Act) made national-origin quotas more restrictive and created a stronger system of overseas visa screening through U.S. consulates. It also helped institutionalize federal border enforcement by authorizing the creation of the U.S. Border Patrol. Together, these changes made transatlantic entry more limited and more paperwork-driven.
The Tydings–McDuffie Act set a path toward Philippine independence and also changed the immigration status of Filipinos for entry to the United States. It reclassified Filipinos as “aliens” for immigration purposes and imposed a very small annual quota. While not a transatlantic measure, it shows how interwar U.S. law used nationality-based rules to shape migration flows.
During World War II, Congress repealed the Chinese Exclusion laws through the Magnuson Act. The law allowed naturalization for Chinese immigrants and set a small annual quota for immigration. Although it had limited numerical impact, it signaled that race-based bans could be rolled back under changing international and political pressures.
The War Brides Act allowed spouses and minor children of U.S. service members to enter as “non-quota” immigrants (not counted against national-origin quotas), if otherwise admissible. This created a major exception to restriction-era rules and helped reunite families formed during World War II. It also foreshadowed later immigration policy that emphasized family ties.
The Alien Fiancées and Fiancés Act (also called the G.I. Fiancée Act) extended the postwar family-reunification approach by allowing certain fiancées of U.S. service members to enter outside the usual quotas. It built on the War Brides Act and was aimed at resolving the practical problem of separating couples after the war. The program contributed to continued migration ties between the United States and European countries in the late 1940s.
After World War II, the Displaced Persons Act authorized a limited-time program to admit large numbers of European displaced persons (people uprooted by the war) for permanent residence. The law responded to the humanitarian crisis in Europe and created a pathway outside the normal restrictive quota framework. This was a major policy-driven transatlantic inflow shaped by postwar conditions.
The Immigration and Nationality Act of 1952 (McCarran–Walter Act) reorganized U.S. immigration law into a single framework and retained the national-origins quota structure that strongly favored some European countries. It also made changes to eligibility and procedures, including rules related to who could become a citizen. For transatlantic migration, the law largely continued restriction-era patterns while updating administration and enforcement.
The Refugee Relief Act created additional admissions for refugees and other special categories outside the normal quota limits. In practice, it supported resettlement linked to Cold War politics and continued postwar European humanitarian needs. The law shows how refugee and “special migration” programs operated as exceptions within a still-restrictive quota era.
President Lyndon B. Johnson signed the Immigration and Nationality Act of 1965 (Hart–Celler Act) at a ceremony at the Statue of Liberty. The law set the direction for dismantling the national-origins quota system that had shaped transatlantic flows since the 1920s. It replaced those rules with a preference system that emphasized family relationships and certain skills.
The 1965 law began a transition period in which unused national-origin quota slots could be pooled and reassigned, rather than remaining locked to underused country quotas. This reduced some of the built-in advantages for countries with high quotas but lower demand and eased pressure for countries with long waiting lists. It was an important step in shifting U.S. policy away from fixed nation-by-nation preference.
On this effective date, the national-origins quota system was fully eliminated and replaced by broader numerical limits, including an overall cap for the Eastern Hemisphere with a per-country maximum. This change closed the main legal framework that had restricted and ranked European immigration since the early 1920s. As a result, transatlantic migration became less dominated by fixed national-origin preferences and more shaped by family-based categories and global demand.
U.S. immigration legislation shaping transatlantic flows (1924–1965)