How long did the Blue Book serve as the primary regulation for NCO duties?

The Blue Book, formally known as the "Regulations for the Order and Discipline of the Troops of the United States," served as the primary regulation for non-commissioned officer (NCO) duties for 30 years. This text was instrumental in establishing standards and expectations for the conduct and responsibilities of NCOs in the U.S. military, shaping the professional development of these leaders within the ranks. During this period, it provided guidance on various aspects of military life, including leadership, discipline, and training, which were critical to building a professional military force.

After 30 years, changes in military structure and the evolving role of NCOs led to the development of more updated regulations and doctrines, underscoring the Blue Book's significance as a foundational document during its time. Understanding the historical context of the Blue Book’s relevance helps in grasping the evolution of military regulations and NCO leadership today.