This guide is a compilation of material concerning American seacoast artillery and seacoast defenses from the earthwork, stone, and brick eras (1794-1876) to the various construction programs of the modern concrete and steel era (1890-1948). Research efforts in this area of history have most often centered on the extraction of information from difficult to find primary source texts, manuals, documents, and reports. This guide covers terms, nomenclature, and data available on this subject, extensively illustrated with historic photographs, drawings, plans, and maps, as well as contemporary photographs. The editor’s intent was to create a series of documents which can be used to introduce the reader to the specifics of American seacoast defenses—the weapons, the structures, the tactical organization, and what can be seen today. Specific sections include American seacoast defense construction periods, terms and definitions, seacoast artillery weapons and emplacements, listings of forts and batteries, antiaircraft artillery, fire control and gun drill, ammunition handling systems, searchlights, mines, radar, coast artillery organization, uniforms, insignia, reservation buildings, and more. Many old coast artillery forts and military reservations have become parks or public lands. This guide was designed to help in the preparation of interpretive signs, brochures, publications, and guided talks for the visitors to these parks. The Coast Defense Study Group (CDSG) is a tax-exempt non-profit corperation dedicated to the study of seacoast fortifications. The purposes of the CDSG include educational research and documentation, preservation and interpretation of historic sites, and assistance to other organizations dedicated to the preservation of coast defense sites.