My dissertation asks how ideas about capitalist development evolved through the experience of implementing Cold War anti-poverty programs, and how ideas circulated between the United States and Latin America. Focusing the Latin American research on Colombia, I examine the ideas of many groups that fought over social policy in both countries: peasants, urban working classes, government officials, capitalists, international financial institutions, academic researchers, and private consultants. The project is a social history of economic thought, in which Cold War reform projects and the social conflicts surrounding them provide the context for studying ideas. I focus on three Colombian programs that generated vigorous international intervention and domestic social conflict: the creation of Colombia’s first regional development corporation in the 1950s, the construction of Latin America’s largest public housing project during the 1960s, and the transformation of the Colombian economics profession during the 1960s and 1970s. I then follow a number of participants in these projects, including Albert O. Hirschman, David Lilienthal, and the Ford Foundation, back to the United States. There, beginning in the late 1960s, they founded community development corporations, organized business school exchanges, and argued for new forms of corporate investment and public administration. These projects provide a historically grounded way of researching the origins of neoliberalism, the international homogenization of economic theory since 1945, and the rise of economists as policymakers and public intellectuals. They also provide a way of studying how different social and national groups understood economic life during the Cold War, and why most people’s ideas were never considered economic thought.