Between 1921 and 1965, policies such as the national origins formula limited immigration and naturalization opportunities for people from areas outside Western Europe. Exclusion laws enacted as early as the 1880s generally prohibited or severely restricted immigration from Asia, and quota laws enacted in the 1920s curtailed Eastern European immigration. The civil rights movement led to the replacement of these ethnic quotas with per-country limits for family-sponsored and employment-based preference visas. Since then, the number of first-generation immigrants living in the United States has quadrupled.