This two-volume work supplies accessible and comprehensive coverage of this complex subject by consolidating the insights of hundreds of scholars who have studied the issues of undocumented immigration in the United States for years. It provides a historical perspective that underscores the exponential growth of the undocumented population in the last three decades and presents a more nuanced, more detailed, and therefore more accurate portrait of undocumented immigrants than is available in general media. Also included are recommended resources that will serve researchers seeking more information on topics regarding undocumented immigrants.