This book traces the origins of the illegal alien in American law and
society, explaining why and how illegal migration became the central
problem in U.S. immigration policy—a process that profoundly shaped ideas
and practices about citizenship, race, and state authority in the twentieth
century. Mae Ngai offers a close reading of the legal regime of restriction
that commenced in the 1920s—its statutory architecture, judicial
genealogies, administrative enforcement, differential treatment of European
and non-European migrants, and long-term effects. She shows that
immigration restriction, particularly national-origin and numerical quotas,
remapped America both by creating new categories of racial difference and
by emphasizing as never before the nation's contiguous land borders and
their patrol.