This research examines the links between business and power, by exploring the type of mediation provided bythe intersection of accounting and cartographic technologies in the definition of the French imperialist project in West Africa at the beginning of the nineteenth century. The period was marked by the abolition of thetransatlantic slave trade after the Congress of Vienna in 1815 and the reorganization of trade networks in the area. The corpus of archives examined contains a thematic map dating from 1839 that provided an accounting appraisal of the economic and commercial potential of the different natural resources of the West African coast, as well as sources relating to the circulation of this map within French political and economic circles. It was based on this map, resulting from an exploration mission mandated by the Ministry of Marine and the Colonies and theBordeaux Chamber of Commerce, that it was decided in 1842 the creation of three fortified trading posts, as well as the signature of treaties (highly favorable to French interests) with the local sovereigns, enabling the establishment of a first trading company from Marseille in 1843. We then seek to answer the following research question: “How did the intersection of cartographic and accounting technologies served as a support for the expression and promotion of a French imperialist project?” To answer this, we mobilize a Foucauldian perspective on maps and accounting technologies, as well as the notion of territorialization developed by Raffestin (1997, 2019). We show that the French imperialist project consisted of a process of social appropriation of space and the resources it conta ins, and that the forms of accounting calculation generated by cartographic technology played an active role in this process. Firstly, from an abstract point of view, by making it possible to identify resources based on a combination of spatial and accounting representations, and from a concrete point of view, by making it possible to develop narratives relating to the market, supplementing the assurance of political and military support from the state, necessary to convince French négociants of the value of the project. This multi-disciplinary work improves our historical understanding of the shaping of relations between power and business, while highlighting the interest in studying the type of mediation made possible by the intersection between the map and the accounting calculation in economic decision-making.