Treatment of migrants and foreigners by a government can reveal not only the functioning of the political system but the philosophic values on which the system is founded. This article compares French and American immigration policy and explores the extent to which French immigration policy is more "statist" or Jacobin while American immigration policy is more "liberal" or pluralist. Immigration is an explosive problem for all democratic governments. 4 questions are involved, that of the sovereignty of the state over its citizens; that of citizenship, not only regarding the juridical definition of citizen but also assimilation, ethnicity, race, and political socialization; that of employment, which has been the most important determinant of migration policies in the industrialized countries after World War II; and that of humanitarian considerations, which have become more significant in the 1980s. Comparison of immigration policies must focus on issues of citizenship and employment and on humanitarian aspects. France and the US have had more difficulty in formulating and applying migration policies with national objectives than have any of the other liberal democracies. This work seeks to explain this similarity as well as divergences in the migration policies of France and the US by examining: 1) institutional differences between the 2 political systems and how they affect the state's capacity to control immigration; 2) the way in which the political and juridical culture influence relationships between problems of citizenship and use of foreign manpower; and 3) immigration policies as they have been applied in the 2 countries in the postwar period. The entire issue of immigration has become more politicized in France than in the US, partly because of the statist and administrative approach to it in France. The federal nature of the US political system, the stability of the party system, and the pluralist approach to legislation have fragmented the issue of immigration to a large extent. Despite significant differences in French and American political systems and cultures, both societies retain a fundamentally liberal attitude toward their foreign populations. The Jacobin ideal of equality before the law held by many French citizens and the liberal ideal of equality of opportunity at the heart of recent American political development explain the openness and attraction of the 2 countries for foreigners.