No federal law had restricted immigration before the 1870s, but the United States had instituted a set of quotas by place of origin, most significantly in the National Origins Act of 1924. By 1970, only 9.6 million Americans, less than 5 percent of the U.S. population, were foreign-born, the lowest percentage in more than a century, and most of these immigrants had come from Europe. By 2000, the number of foreign-born Americans had risen to 31 million, constituting 11 percent of the U.S. population. Most of these newer immigrants were from Latin America and East Asia.
