Francisco Javier Saenz de Oiza was a pioneer in Spain in his time. His development as an architect and his teachings were marked by a trip that took him to the United States for almost a year. In 1948, shortly after obtaining his degree, he won the Conde de Cartagena scholarship, which allowed him to be trained in a country little known for most of his compatriots at that time. Thanks to the discovery of the letters that he sent monthly to the San Fernando Academy of Fine Arts, it has been possible to reconstruct his trip step by step, the places he visited, the contacts he made, his research topics, and the encountered difficulties. In this way, it is possible to understand its mark, which allows us to obtain lessons to get the most out of the trips that architecture professionals continue to make around the world.