The origins of modern mathematics in continental Europe and New Math in the United States can be situated in the early 1950s, and although both educational reform movements share common sources and motives (and are often seen as one and the same movement), they initially developed independently of each other. In this chapter, we examine how and why both movements emerged in Europe and the US. The revision of secondary school programs in light of a modernization of undergraduate instruction in mathematics and science was a concern on both sides of the Atlantic. In Europe debates were mainly related to scientific innovations, such as the work of Bourbaki in pure mathematics and that of Swiss psychologist Jean Piaget in developmental psychology. The American movement was stronger rooted in socio-political and economic motives, such as the demand for mathematically trained manpower, and was government-driven early on.