During the early twentieth century US occupation of Haiti, marines turned to education and public health in the face of international criticism of the occupation's brutality. Drawing on primary archival research in Haiti and the US, this article discusses the Service Technique – an agricultural and vocational education and training program that marked the US occupation's turn toward development and humanitarianism as weapons. This previously unexamined archival material illustrates how militarized development projects provided fertile terrain for the acceleration of anti-occupation movements rather than recuperating occupation as intended. This discussion makes key contributions to Haitian historiographies, which largely neglect the period after the occupation's transition to development, as well as to literature on the cultural and historical geographies of militarism and development more broadly. The story of the Service Technique changes existing periodizations of development's birth out of colonial counterinsurgency, pointing to the neglected geography of Haiti, the earlier period of the 1920s, and the role of US imperialism in the historical geography of militarized development.