In many books, the authors ignore vital parts of their subjects' lives. Too often these writers purposely refuse to identify the religion, political party or fraternal memberships of their heroes. And yet these very controversial elements of life actually shape the pattern of behavior for every human being. To truly know a person, one must first examine his organizations and his friends. Armed with this knowledge, we can better understand why a man or woman acted as he or she did under certain circumstances. For instance, Masonry is a way of life, and so readers will find fraternal identifications in the body of this book as well as in the lengthy footnotes. Also, this author has in every case attempted to learn the religious and political preference for every major figure mentioned in this work. Such a task has not been easy, but it is felt that the results are well worth the effort which has been expended to dig out this elusive information. The title for this treatise comes from the fact that the square and compasses were the most important measuring tools used in constructing or remodeling the Lincoln home. Then, too, so many of the builders, occupants or persons involved with this residence were either speculative or operative masons that it was thought this title fit the story extremely well. Readers will discover that this volume is written from many previously unknown sources and is a new contribution to the Lincoln saga. It is hoped that they will enjoy this tale as much as the author did in assembling it, writing it down, and lecturing about it.