Chinese immigration in America in the mid-nineteenth century incited violence and governmental sanctions to restrict Asian immigration and reject citizenship rights. In 1870, Chinese strikebreakers in Massachusetts ignited nationwide demonstrations against Chinese immigration, which ended altogether with the Chinese Exclusion Act (1882). Japanese schoolchildren in San Francisco public schools sparked rioting in 1907, leading Japan to unilaterally limit emigration to the United States (Gentlemen's Agreement, 1908). Congress responded to anti-Punjabi riots (Bellingham, WA, 1907) by refusing naturalization rights to Asians (Barred Zone Act, 1917), policies supported by the Supreme Court (Ozawa, 1922; Thind, 1923). All immigration from Asia was soon prohibited (Johnson-Reed Act, 1924). Anti-Asian measures peaked in 1942 with imprisonment of Japanese in concentration camps, including those with birthright citizenship. Anti-Asian policies unwound in the last half of the 20th century, culminating in sweeping changes in US immunization policy. Naturalization rights were granted to wartime allies against Japan (China, 1943; the Philippines and India, 1946) and the Japanese themselves (1952). Asian women marrying American servicemen were allowed entry into the country (1945, 1950). Prohibitions against Asian immigration were lifted in 1965 (Hart-Celler Act), with preference for those trained in science, technology, and medicine. The refugee crisis that followed the fall of Saigon (1975) drove humanitarian policies that brought evacuees from Southeast Asia and others from throughout the world seeking freedom from persecution (Refugee Act, 1980). Hundreds of thousands from China, South Asia, the Philippines, and Southeast Asia thus settled in the United States, changing American society and medicine.