This historical essay critically examines the early military settlement projects realized by the French Engineering Corps in Senegal and the Western Sudan during the second half of the 19th century. The French were preoccupied with the establishment of official control over the hinterland, confronting a variety of challenges in situ. In striving to go beyond the prestigious image of the Corps and the discourse on colonial settlement forms as an instrument for domination, this article exposes aspects of uncertainty and haphazardness behind the projects. Visual correspondence with indigenous cultures is expanded, employing a rich variety of historical sources.