In May 1963, thirty-two independent African States, who had genuine hopes and visions for the continent of Africa, came together in Addis Ababa, Ethiopia, to create the Organization of African Unity (OAU).
In order to strengthen the continent of Africa and to make it less vulnerable to outside influence, President Kwame Nkrumah of Ghana strongly believed that the continent should be united.
Thus, in the late 1950s, Dr. Kwame Nkrumah started a movement, which stressed the immediate unity of the African continent.
When Dr. Kwame Nkrumah introduced the concept of African Unity to the continent, a division, which was based on the implementation of this new concept, was created at the onset.
On one hand there were those countries which believed in the immediate unity of Africa.
These countries were originally Ghana, Guinea, and Mali. Later on Egypt, the Transitional Government of Algeria, and Morocco, joined the Ghana-Guinea-Mali Union to form the Casablanca Group.
On the other hand, the twenty-four member Monrovia Group, otherwise known as the Conservatives, which included Nigeria, Liberia, Senegal, Ivory Coast, Cameroon, Togo, and many others believed in a much more gradual approach to the question of African Unity.
Many believed that the rift between the two groups would become permanent and thus ending the hopes and dreams of African Unity.
Yet, in May 1963, these two opposing groups were able to come together to form the Organization of African Unity.
Established: May 25, 1963 Purpose: to promote unity and cooperation among African states.
Membership: 53 members.
Algeria, 1963; Benin, 1963; Burkina Faso, 1963;Burundi, 1963; Cameroon, 1963;
Central African Republic,1963;Chad, 1963;Democratic Republic of the Congo, 1963;
Republic of the Congo, 1963; Côte d´Ivoire, 1963 Egypt, 1963;Ethiopia, 1963;
Gabon, 1963; Ghana, 1963;Guinea, 1963; Kenya, 1963; Liberia, 1963;
Libya, 1963 Madagascar, 1963;Mali, 1963; Mauritania, 1963; Niger, 1963;
Nigeria, 1963; Rwanda, 1963; Sahrawi Arab Democratic Republic;
Senegal, 1963; Sierra Leone, 1963; Somalia, 1963 Sudan, 1963;
Tanzania, 1963; Togo, 1963;Tunisia, 1963;Uganda, 1963;
Malawi, 1964 Zambia, 1964; The Gambia, 1965 Botswana, 1966;
Lesotho, 1966 Equatorial Guinea, 1968; Mauritius, 1968 Swaziland, 1968
Guinea-Bissau, 1974 Angola, 1975; Cape Verde, 1975; Comoros, 1975;
Mozambique, 1975 São Tomé and Príncipe, 1975 Seychelles, 1976
Djibouti, 1977;Zimbabwe, 1980; Namibia, 1990; Eritrea, 1993; South Africa, 1994.

The Organisation of African Unity (OAU or Organisation de l'Unité Africaine (OUA)) was established on May 25, 1963.
It was disbanded July 9, 2002 by its last president South African Thabo Mbeki and replaced by the African Union.