Using recently declassified material, this thesis traces the Commandant Thomas Holcomb' s role in the development of the Marine Corps Defense Battalion. It thus combines biographical and institutional history. Holcomb was an excellent strategist, manager, and publicist. The defense battalion provides a case study for examining Holcomb's leadership as well as the larger historical context. On a tactical level, planners designed these units to defend island outposts against air, sea, and amphibious assaults. In holding island bases in the western Pacific, defense battalions fit into the grand strategy of the United States Navy. The units comprised one half of the Corps's dual mission: amphibious assault and base defense. Defense battalions also served an equally pivotal public relations function as Holcomb struggled -albeit with little success -- to secure scarce resources for the Corps. Understanding Holcomb's actions and the defense battalion's development illuminates the mentality of America's military and government before World War II.