In 1924–34, the Congo-Ocean Railway (CFCO) was built at a considerable human and financial cost, opening the way for growth of the ocean port of Pointe-Noire and towns along its route.

Congo benefited from the postwar expansion of colonial administrative and infrastructure spending as a result of its central geographic location within AEF and the federal capital at Brazzaville.

The Loi Cadre (framework law) of 1956 ended dual voting roles and provided for partial self-government for the individual overseas territories.

The principal element in the French-Congolese relationship was the highly successful oil sector investment of the French petroleum parastatal Elf-Aquitaine (now called Total), which entered the Congo in 1968 and has continued to grow.

France is now by far Congo's principal external partner, contributing significant amounts of economic assistance, while playing a highly influential role.