I feel like there is a lot of information on how the Democratic Republic of the Congo gained independence and why but almost no information on how Congo Brazzaville did. And even if there is information, it's really hard to find. Help please?
You are right, there is much more written about the decolonization of DRC than is written about Congo-Brazzaville.
There are a handful of reasons for this: the French government and scholarship writing in the 1960s portrayed the independence process in the 1950s up to 1960 as orderly and peaceful. This is in contrast to the Congo Crisis which immediately beset Congo-Leopoldville after independence.
Another reason is that Moyen Congo/Congo-Brazzaville had slightly over 1 million people in 1960; where Belgian Congo/Congo-Leopoldville had over 15 million. In 2020, Congo-Brazzaville has only about 5.5 million people where DRC has almost 90 million people, so that disparity continues. Additionally, because of the large population and geographic extent of DRC, the political stability of DRC had large implications for the many neighbors. That drew a great deal of scholarly interest trying to understand how US, French, Soviet, Chinese and Belgian policy towards Lumumba, Kasa-Vubu, Mobutu and Mulele shaped the Cold War in Central Africa. The small size of Congo-Brazzaville gave the impression to American diplomats and scholars that it was not very influential in Cold War terms (although France did pay diplomatic attention).
Finally because 14 French colonies in West Africa and Central Africa plus Madagascar, gained full independence in 1960, what scholarship there is has tended to analyze this cohort. Furthermore, the anglophone scholarship has tended to emphasize the politics and philosophy of West African individuals like Senghor and Houphouet-Boigny and Sekou Toure as drivers towards independence, de-emphasizing Gabonese or Centafrican or Congolese voices. Francophone scholarship began to re-examine the "orderly and peaceful" narrative and study 1950s independence politics of Gabon, Moyen Congo, Ubangi-Chari since about 2000. That trend seems to be making a limited cross-over into Anglophone scholarship recently.
With that preamble in mind, my answer is going to follow the top-down approach that focuses on French colonial policy and legislative change from 1940-1960 and how that impacted West African and Central African colonies. I will try to give special attention to Moyen Congo/Congo-Brazzaville, but TBH my knowledge in that area is limited.
In the summer of 1940, the armies of Germany overran northern France and forced the capitulation of the Third republic. What followed was a German military occupation of the Atlantic coast and establishment of a collaborationist Vichy regime led by marshal Phillipe Petain.
In France's colonies in the Caribbean, Africa and Indochina; the vast majority of colonial governors accepted the Vichy regime as the legitimate successor of the 3rd republic. In Central Africa, the colonial governor Felix Eboue of Chad refused to recognize Vichy legitimacy and declared allegiance to Charles DeGaulle and the Free French forces who sought to continue fighting Nazi Germany. Soon after, General Leclerc arrived in Douala in Cameroon and that mandate territory declared allegiance to Free French. The governors of Oubangi-Chari and Moyen Congo would also pledge allegiance to Free French in the fall of 1940.
In 1941, Free French armies would launch military offensives against Vichy loyalist regimes in Gabon. In the autumn of 1942, British and American landings in Operation Torch succeeded when Vichy governor of Algeria, Francois Darlan, struck a deal to change sides. Darlan was eventually assassinated and DeGaulle nominated a Free French loyalist to replace Darlan as governor of Algeria. With North Africa and Central Africa now loyal to Free French forces, and the war in Europe now seeming to be moving in favor of US, UK and Free French; the Vichy governors of West African colonies now switched loyalties and declared support for Free France in 1943.
In January of 1944, the prospects of an allied invasion of France became immanent. General DeGaulle and his political advisers felt that to protect Free French political position and future of French Empire against President Roosevelt's anti-colonial attitudes (expressed in the Atlantic Charter), Free French must ensure the recruitment of FF soldiers in North, Central and West Africa to participate in the campaign. So, in January of 1941 the Brazzaville Conference was held, where French colonial administrators in Africa consulted and pledged several concessions once the war ended.
These concessions were:
Each of these concessions was eventually incorporated into the constitution of the French fourth republic in 1946. However, the way that some of these concessions were handled generated new discontents. The recognition of native courts tended to strengthen the power of traditional chiefs. However, back in the 1920s the colonial authorities had dismantled many of the traditional chiefdoms, so the return of power to chiefdoms often meant the reconstitution of these offices. Office holders from the 1920s alleged that French authorities used this opportunity to raise up their favorites, creatures who could be relied upon to follow the wishes of colonial governors.
Also, elections had several flaws. French administration in West Africa and Central Africa consisted of federations of colonies (Afrique Occidental Francaise and Afrique Equatoreal Francaise respectively). Educated African politicians like Leopold Senghor and Felix Houphouet-Boigny disagreed whether legislative assemblies should exist only at the federation-level or at the level of individual colonies. Notionally, a Governor General (in charge of a federation) had expansive powers and governors of individual colonies were supposed to take orders from the Governors General in Dakar and Brazzaville. Thus, strong legislatures in Dakar and Brazzaville would be useful to counsel and check the power of Governors General.
However, on the other hand, Houphouet-Boigny might argue that the voice of people in Cote d'Ivoire might not be heard in Dakar, and legislatures should be devolved to each colony to be more responsive to local public demands.
Also, at the metropolitan level, elections to the National Assembly proceeded on a separated system of colleges. That is to say, the White colons in each colony were allocated an elected representative. On the other hand, only educated male Africans who had been granted citizenship could vote for representatives to Paris. So, where there might be 2.5 million people in Cote d'Ivoire in 1948, 3,000 white colons might be allocated 1 representative, and 12,000 evoluee citizens might be allocated 4 representatives. So, while there were 40 million French citizens in European France and 60 million subjects in West Africa, Central Africa, Madagascar and Indochina, representatives from France were the overwhelming majority in the National Assembly.
Shifting gears slightly, we also should pay attention to how the armed liberation struggle in Indochina and Algeria created pressure on France to decolonize.
As soon as Japanese troops withdrew from Indochina in 1945, France faced armed resistance from the Viet Minh national liberation movement. France faced enormous problems transporting soldiers and materiel to the other side of the world to combat a guerrilla insurgency, especially while trying to rebuild from WW2. After the defeat at Dien Bien Phu in 1954, France was forced to withdraw from Indochina and recognize the independence of Vietnam, Laos and Cambodia.
Just as French troops were pulling out of Indochina, political unrest in Algeria which had been burning slowly since the 1930s entered an armed phase in 1954. Algeria was legally an overseas department of France with a European population of over 1 million, and so there was intense pressure to fight to keep Algeria.
This Algerian war was enormously controversial within Algeria and within France, and prompted fierce criticism from the French Communist Party and anti-colonialist thinkers, who were opposed by the French right and arch-conservative settler movement in Algeria. The election of a socialist government in 1958 raised fears in settlers and in the army that the government would seek to negotiate independence for Algeria. So, elements of the French army in Algeria launched a coup in May 1958, overthrowing the 4th republic and seeking to bring Charles DeGaulle out of retirement to serve as President.
Charles DeGaulle did accept the presidency to resolve the political crisis the coup created, but he refused to become a pawn of the army plotters. He insisted on the drafting of a new constitution that would increase the power of the President, so that he could effectively deal with a crisis like the May coup in the future. The new constitution required approval by referendum in France.
Additionally, at the same time as the constitutional referendum was being organized in France, DeGaulle sought referenda in 15 French colonies in West Africa, Central Africa and Madagascar to determine their status vis-a-vis France. The options in these referenda were:
Only Guinea under Sekou Toure voted for the option of immediate independence. Every other colony approved of membership in the French Community, though Charles DeGaulle put his thumb on the scale when he declared in Brazzaville before the referenda that colonies which chose membership in the Community could declare independence at a later date.
Continued...