For more than 30 years, J. Gordon Melton has attempted to document the growing religious diversity in the United States. From the beginning, his directory has included entries for every American church with two or more congregations or a single congregation of more than 2,000 members. The chief exceptions made to these criteria have been for groups at the fringes of traditional practices, including cults and new religious bodies. All told, Melton identifies more than 2,300 religious bodies operation within the United States and provides both contact and membership information. However, Melton’s guide has always been more than a simple directory. He discusses the origins of each group, identifying related parent and splinter organizations. Distinctive beliefs and histories are outlined. For larger groups, an analysis is made of its organization and a list provided of associated educational facilities. In past editions, Melton summarized associated texts; he now provides bibliographies of sources available for the study of each group. One of the great values of this encyclopedia has been Melton’s attempt to classify religious bodies in the United States. The guide divides religious groups into 26 broad denominational categories ranging from Interfaith, Catholic and Lutheran Christian organizations to South Asian and Far Eastern religions. Many of these broad groups—like the Baptist and Adventist families include—multiple subdivisions. Each chapter includes an expert-written overview of the history and distinguishing features of the denomination. More than 200 new churches are included in this edition. Another added feature is an appendix of more than 500 defunct churches. Entries for these inactive groups are substantial with historical information comparable to the active entries. A geographical appendix lists organization by their headquarters city. The detailed index includes individuals, publications and general subjects as well as churches, denominations and related organizations. This update of an outstanding work also is available electronically and is highly recommended for academic and public libraries.