This work, the ninth in a series of books about Maryland families, focuses on the Purdum families, primarily of Montgomery and Frederick Counties. Having early origins in the area, and being rather prolific, the Purdum families intermarried with many of those families found in the first eight books of his series, and some of the information presented there will be repeated here, rather than requiring the reader to move back and forth between the various volumes in the series. Following the custom of the earlier works in this series, the book begins with a look at the early history of the Maryland Colony and the formation of the counties. From there, it moves into early Purdum family records, including John Purdum (born before 1700), who appears to be the progenitor of virtually all of the Purdums thus far identified in the study. John had at least four children, one of whom was James Purdum (born about 1720). James had at least one son, and probably several other children, but the one that the author has identified is yet another John Purdum (born about 1739). Individual chapters focus on: John Purdum and his family of at least eleven children, Walter Purdum, the descendants of Joshua Purdum, and others. Some family members, not identified within the framework of the principal family study are also touched on. A bibliography of over 100 titles testifies to the wide range of sources used in this compilation, and a full-name index supplies over 4,500 names. This book is a must for anyone researching the Purdum surname in this area.