The United States has had a complex relationship with the end of European colonialism. Despite vocal support for self-determination and anti-imperialism, American complicity with languishing European empires and an aggressive Cold War policy placed the US in a distinctly ‘imperialist’ position during the middle years of the twentieth century. Drawing on this context, this paper examines the ‘decolonisation’ of the US national collection of ethnographic artefacts between 1945 and 1970. It examines how ‘Africa’ and ‘Asia’ were reimagined through material culture and exhibition design by curators and visitors to the National Museum of Natural History in Washington, DC, in light of the ‘end of empire’, as well as considering the perspectives of the decolonising governments and cultural agencies with which the museum worked.