Encoded Archival Description (EAD), the SGML Document Type Definition (DTD) for archival finding aids, has been under development for more than three years. Although it has been significantly improved during that time by feedback from early implementers and by new insights from its developers, much of EAD's basic structure dates from the design team's first meeting in July 1995 at the Bentley Historical Library in Ann Arbor, Michigan. During that week-long gathering, the EAD design team articulated its observations about traditional archival finding aids, established design goals and principles, and created the framework for the current version 1.0 DTD structure. This article examines the basic steps in building an SGML DTD and provides a structural analysis of EAD's high-level elements in light of the developers' early design goals and decisions.