The Great American Mission traces how America's global modernization efforts during the twentieth century were a means to remake the world in its own image. David Ekbladh shows that the emerging concept of modernization combined existing development ideas from the Depression. He describes how ambitious New Deal programs like the Tennessee Valley Authority became symbols of American liberalism's ability to marshal the social sciences, state planning, civil society, and technology to produce extensive social and economic change. For proponents, it became a valuable weapon to check the influence of menacing ideologies such as Fascism and Communism.

Modernization took on profound geopolitical importance as the United States grappled with these threats. After World War II, modernization remained a means to contain the growing influence of the Soviet Union. Ekbladh demonstrates how U.S.-led nation-building efforts in global hot spots, enlisting an array of nongovernmental groups and international organizations, were a basic part of American strategy in the Cold War.

However, a close connection to the Vietnam War and the upheavals of the 1960s would discredit modernization. The end of the Cold War further obscured modernization's mission, but many of its assumptions regained prominence after September 11 as the United States moved to contain new threats. Using new sources and perspectives, The Great American Mission offers new and challenging interpretations of America's ideological motivations and humanitarian responsibilities abroad.