Thousands of Cameroonian women played an essential role in the radically anti-colonial nationalist movement led by the Union of the Populations of Cameroon (UPC): they were the women of the Democratic Union of Cameroonian Women (UDEFEC). Drawing on women nationalists' petitions to the United Nations, one of the largest collections of political documents written by African women during the decolonization era, as well as archival research and oral interviews, this work shows how UDEFEC transcended ethnic, class, education and social divides, and popularized nationalism in both urban and rural areas through the Trust Territories of the Cameroons under French and British administration. Foregrounding issues such as economic autonomy and biological and agricultural fertility, UDEFEC politics wove anti-imperial democracy and notions of universal human rights into locally rooted political cultures and histories. UDEFEC's history sheds light on the essential components of women's successful political mobilization in Africa, and contributes to the discussion of women's involvement in nationalist movements in formerly colonized territories.