Ghana gained independence on March 6, 1957, when Kwame Nkrumah declared independence before 50,000 people in Accra, making it the first sub-Saharan African country to break from European colonization. In 1960, seventeen additional nations gained independence: Cameroon, Togo, Senegal, Mali, Madagascar, Democratic Republic of Congo, Benin, Niger, Burkina Faso, Ivory Coast, Chad, Central African Republic, Congo-Brazzaville, Gabon, Nigeria, Mauritania, and Somalia. By decade's end, Africa had 48 independent nations. However, instability followed. Patrice Lumumba, Congo's first Prime Minister, was executed in 1961 with alleged Belgian and CIA involvement. Nkrumah was overthrown in 1966.