2019 Theodore Roosevelt Association Book Prize Although Theodore Roosevelt was not a wartime president, he took his role as commander in chief very seriously. In Command explores Roosevelt’s efforts to modernize the American military before, during, and after his presidency (1901–9). Matthew Oyos examines the evolution of Roosevelt’s ideas about military force in the age of industry and explores his drive to promote new institutions of command: technological innovations, militia reform, and international military missions. Oyos places these developments into broader themes of Progressive Era reform, civil-military tensions, and Roosevelt’s ideas of national cultural vitality and civic duty.In Command focuses on Roosevelt’s career-long commitment to transforming the military institutions of the United States. Roosevelt’s promotion of innovative military technologies, his desire to inject the officer corps with fresh vigor, and his role in building new institutions for command changed the American military landscape. His attempt to modernize the military while struggling with the changing nature of warfare during his time resonates with and provides unique insight into the challenges presented by today’s rapidly changing strategic environment.