Immigration restriction became a favored method for nativists and special interests in the "clash of cultures" at the turn of the century. While few restrictions prevented immigration to the U.S. before 1900, interest groups did succeed in pressuring the federal government to exclude unwelcome immigrants - prostitutes (originally Asian women), convicts, contract laborers, the mentally ill, and the diseased - and in some cases the government imposed a head tax on new arrivals. As a result of pressure from western states and nativist organizations, the federal government enacted laws that specifically targeted Asian immigrants, such as the Chinese Exclusion Act in 1882 and the "Gentlemen's Agreement" with Japan in 1907.

By the early twentieth century, organized labor, nationalist and nativist organizations, temperance organizations and, at various times, farmers and manufacturers, lobbied Congress to regulate the flow of "new" immigrants by imposing literacy requirements. Twenty years after it was first proposed, Congress finally passed (over President Wilson's veto) a law in 1917 that required literacy tests for new immigrants . The First World War slowed immigration to the U.S. but, after the armistice, mass immigration resumed, reaching 805,000 in 1921.