The purpose of the article is to establish and assess the significance of the federal legacy of the Schuman Declaration (9 May 1950) in the evolution of postwar European integration. To this end it provides a sharp focus upon the political strategy of Jean Monnet and his active role in promoting the cause of a federal Europe. His approach to the building of Europe is outlined and its direct relationship to the Schuman Declaration, which he wrote, is explored. Monnet's conception of Europe is confirmed as federal and the author draws upon the theoretical concepts of supranationalism and intergovernmentalism in order to demonstrate precisely how Europe's first construction, the European Coal and Steel Community (ECSC) created in 1951, was illustrative of a distinctly new and unprecedented form of European integration. The conclusion confirms this to be incremental federalization.