In the early years of the twentieth century, Herbert Eugene Bolton opened up a new area of study in American history: the Spanish Borderlands. His research took him to the archives of Mexico, where he found a wealth of unpublished, even unknown, material that shed new light on the early history of North America, particularly the American Southwest. The seventeen essays in this book, edited by John Francis Bannon, illustrate the importance of his contributions to American historiography and provide a solid foundation for students of Borderlands history.