Who was recognized for significantly modernizing the Marine Corps?

General John Lejeune is recognized for significantly modernizing the Marine Corps primarily during his tenure as Commandant from 1920 to 1929. He played a crucial role in transitioning the Marine Corps into a more modern military organization. Lejeune was instrumental in advocating for the development of new tactics and the establishment of amphibious warfare as a core competency. His focus on education and training transformed the Corps, emphasizing the importance of warfighting doctrine and enhancing the capabilities of the Marines.

Additionally, Lejeune was pivotal in promoting the significance of combining land, air, and sea power, which laid the foundation for future operations. His leadership in the post-World War I era helped to shape the Marine Corps into a more agile and effective fighting force, ensuring that it could respond to the demands of modern warfare. The legacy of his modernization efforts continues to influence the Marine Corps' structure, mission, and strategic approach today.