1942: Labor shortages during World War II prompted the United States and Mexico to form the Bracero Program, which allowed Mexican agricultural workers to enter the United States temporarily. The program lasted until 1964.

1948: The United States passed the nation’s first refugee and resettlement law to deal with the influx of Europeans seeking permanent residence in the United States after World War II.

1952: The McCarran-Walter Act formally ends the exclusion of Asian immigrants to the United States.

1956-1957: The United States admitted roughly 38,000 immigrants from Hungary after a failed uprising against the Soviet Union. They were among the first Cold War refugees. The United States would admit over 3 million refugees during the Cold War.

1960-1962: Roughly 14,000 unaccompanied children flee Fidel Castro’s Cuba and come to the United States as part of a secret, anti-Communism program called Operation Peter Pan.