This work explores the history of the dispute between the U.S. Army and Navy during World War II over which service would control land-based antisubmarine aviation in the Battle of the Atlantic. Additionally, this work seeks to explore the relationship of this wartime dispute to the post-war military unification movement which culminated in the passage of the National Security Act of 1947. Many lessons learned through the management of the extemporized wartime defense bureaucracy convinced political and military leaders of the need to develop an integrated post-war military-intelligence-diplomatic apparatus for the purpose of defending against foreign threats to national security. In most studies of the issues underlying the 1947 National Security Act, the focus tends to be on those which gave rise to lingering questions touching upon politics and military policy into the Cold War era. These include: the scope and limitations of authority of the Central Intelligence Agency; the control and use of nuclear weapons; the roles and missions of the Army, Navy and independent Air Force; the institutionalization of the Joint Chiefs of Staff; and the extent of power exercised by the newly created Secretary of Defense over the unified armed forces. This study in no way seeks to detract from these issues as the overriding concerns which shaped the debate leading to the National Security Act's passage. While acknowledging the primacy of these issues, however, it is the contention of this present study that the question concerning which military service should rightly control land-based antisubmarine aviation during World War II has largely been overlooked as a significant issue in shaping the military unification debate. This work intends to take what most other studies relegate to a footnote and explore, in significantly greater depth, how this inter-service rivalry affected the wartime management of the Battle of the Atlantic and how, in turn, the wartime interservice rivalry helped shape the post-war military unification debate culminating in the passage of the National Security Act of 1947.