Table 1 shows that the single biggest recipient of immigrants was the United
States. Since Congress enacted the 1965 Immigration Act, which ended quotas
based on national origin, immigration to the United States has increased greatly. In
1964–69, Canada, Australia and New Zealand admitted more immigrants than the
United States, but by 2000–2002, the United States admitted more than twice as
many immigrants as these countries. In 2000, the 35 million immigrants to the
United States constituted 12.4 percent of the population, up from 4.7 percent in
1970. Because most immigrants are of working age, the immigrant proportion of
persons aged 25–39 was higher at 19.4 percent. Immigrants made up approximately
half of the 1990s job growth in the United States and added 2.3 million new workers
during the slower job growth of March 2000 to March 2004, when native-born
employment was roughly constant (Camarota, 2004, Table 1).