This volume investigates the structural evolution and organizational hierarchy of the United States Army from the post-Civil War era through the late 20th century. John B. Wilson, a historian with the U.S. Army Center of Military History, utilizes archival records and official unit histories to document the formation and dissolution of major combat formations. The text provides a systematic framework for understanding how the Army adapted its command structures to meet changing geopolitical requirements and technological advancements.

Historians and military researchers frequently cite this work as a foundational reference for understanding the administrative structure of the U.S. Army. The text is noted for its high density of technical data and its utility as a primary resource for institutional military research.