Mexicans currently constitute the largest nationality of immigrants, legal and undocumented, to the United States. In 2011, approximately 11.7 million Mexican immigrants were living in the United States, with more than half of them living in just two states, California and Texas. Mexican migration to the United States has been one of the defining features of U.S.-Mexican relations since the early 20th century. Although immigrants enter the United States for a variety of reasons, such as to flee warfare or political persecution and to reunite with family members, the history of Mexican immigration has primarily been labor driven, fueled by significant economic develop­ments on both sides of the border. Although much of the contemporary social and political debate surrounding illegal immigration focuses on undocumented Mexican ...