Genealogists and other historical researchers have valued the first two editions (1984, 1997) of this work, often referred to as “the genealogist's bible.” The new edition continues that tradition, and many libraries will want to acquire it. This time around, technological advances have drastically altered genealogical research. Computers and the Internet make many sources more accessible and more easily searched, and genetic data has entered the scene. Intended as a handbook and a guide to selecting, locating, and using appropriate primary and secondary sources, The Source also functions as an instructional tool for novice genealogists and a refresher course for experienced researchers. More than 30 experts in this field—genealogists, historians, librarians, and archivists—prepared the 20 signed chapters, which are well written, easy to read, and include many helpful hints for getting the most out of whatever information is acquired. For example, the undated photograph on page 9 of a Mexican village can be roughly dated by knowing that the volcano in the background was active for only a few years, 1943-52. There are four new chapters: “Computers and Technology,” “General Reference and Guides,” “Colonial English Research,” and “Colonial Spanish Borderland Research.” Three chapters were rewritten (“Business, Institution and Organization Records,” “Church Records,” and “African-American Research”), and all of the others have been updated to reflect new sources and new techniques. Each chapter ends with an extensive bibliography and is further enriched by tables, black-and-white illustrations, and examples of documents. Eight appendixes include the expected contact information for groups and institutions that persons studying genealogy and history need to find, such as family associations, historical societies, and archives.