This paper, written for a conference at the Radcliffe Institute, analyzes the state of immigrant incorporation in the U.S. in the post-9/11 era. After identifying the pivotal legal and political developments in immigration policy during the last decade, I discuss five elements of the incorporation phenomenon: (1) public attitudes toward immigration and (what is not always the same) toward immigrants, as well as the diversity that immigration brings to American life, (2) the role that affirmative action and other public benefits play in the incorporation of immigrants, (3) the role of federalism in structuring immigrant incorporation, (4) emergent notions of citizenship, and (5) the nature and extent of immigrant assimilation. The analysis includes some comparative references to recent developments in Canada and western Europe.