<P> In 1952, the McCarran Walter Immigration Act 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 . </P> <P> In 1954, Operation Wetback forced the return of thousands of illegal immigrants to Mexico . 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 under way, 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 . </P> <P> 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, bringing in 245,000 new Hungarian families 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 new arrivals from the Netherlands, 203,000 from the UK, 46,000 from Japan, 300,000 from Mexico, and 377,000 from Canada . </P> <P> 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 . 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 . </P>

Immigration from europe reached its peak in the years before world war 1