The author holds that over the past generation the understanding of American history has been altered by contributions to the literature that have opened up entirely new areas of knowledge. The influences of the so-called “new” sub-fields of United States history—social, cultural, women’s, labor, union, western history, etc. —on the study of Chicanas/os have been profound. Unlike the other major immigrant and racial minority groups in the U.S., Mexican Americans were largely excluded from historical analysis. During the last quarter of the twentieth century, this exclusion has been addressed through the works of a few pioneering scholars who helped to define the early historiography. The first cohort of Ph.D.’s trained as specialists in Chicana/o history laid the foundation for the development of this field during the 1970s and 1980s.The author examined in his first book, Chicanos in a Changing Society, published in 1979, a reflection of the initial stages of historical scholarship in Chicana/o history. The primary purpose of this book was to contribute to the recovery and reconstruction of an ignored and obscured past—a history of people of Mexican origin in the Southwest who were cast into the shadows and omitted from historical consideration. Recent literature on Chicana/o history differ in both scope and chronology, but four areas have attracted the attention of historians: urban communities, workers in urban and rural areas, women, and political and institutional histories.