Since the second half of the 1950s, on the wave of the colonial decline, Africa saw competing political visions at play. By the summer of 1960, the Congolese crisis called into question all the thorniest questions of independence - from the relationship with the former metropolis to the contents of a full national sovereignty, from international alliances to the role of resources, from territorial integrity to respect for divergent local and regional claims. The crisis therefore marked a turning point. From then on, Cold War rules and constraints would make it much more difficult to elaborate and implement alternative designs to the strategies of the superpowers and their allies. Pan-Africanism itself, tugged between national and partisan interests, came to be challenged. This contribution, based on multi-archival sources, investigates exactly that period by focusing on three issues: the form of government (unitary or federal) to be given to the independent Congo, the involvement of the United Nations and the role of African diplomacy during the crisis.