The Agreements of Madrid were signed in 1953. In them, Spain started to be an ally of the United States of America. In those years, the Spanish public opinion was anti-American because of different reasons. The American Information Services used their available tools to show the population a positive view of their country, in order to obtain the need support to the renovation of the Agreements in a close future. The emigration to America of some of the great Architectural masters and the development of the technology and the industry, placed the USA in a leading role in the architectural field. As they were conscious of it, they used architecture as a political tool, showing in Spain an image of the modern architecture and the American cities really attractive. The aim of this article is to study the role of the American Embassy in Madrid and the entities that directly depended on it in the spreading of the American Modern Architecture in Spain.