By the beginning of World War I most U.S. American children attended elementary school. However, up to 65% of school age children left their studies to find work after the fifth or sixth grade when they were ten or eleven years old. Four years after the stock market crash of 1929 one quarter of the labor force, or thirteen million workers of all ages, found themselves unemployed, and would-be young workers remained in school as students advancing into the higher grades. The author discusses the history of reorganization and consolidation of Rockefeller related philanthropic boards in 1928 that allowed for a coordinated response to the social crisis of education and youth. As ideological institutions Rockefeller philanthropies' activities in the 1930s were based on the idea that experts with a "scientific" understanding of how human beings develop and how social organizations function could apply their knowledge to restructure basic social institutions, such as the school, with specific advantageous outcomes for particular populations, such as youth. Recognizing the continuing evolution of the student population, the author concludes by noting that the crisis of youth in the 1930s became a new kind of crisis in the 1950s and 1960s. Universal access to secondary education, the new applied humanities, popularization of child development research on adolescents, and the explosion of new mass medias served to create a new being, the modern teenager