The emergence of railroads in France in the nineteenth century raised new debates on analytical issues. The issue lies in the fact that they are natural monopolies. In this paper, I focus on Jules Dupuit’s work on the operations of the railroads. Curiously, he seemed to have defended two contrasting positions: on the one hand, he claimed that unlimited competition is the most effi cient way to operate in the railroads; on the other, he stated that State management was the best way to run them. I aim to restore the consistency of Dupuit’s positions. I show that, for him, unlimited competition is not possible in the railroads and that it is not necessarily good for the welfare of society. Therefore, the State should regulate this sector. Then, I specify the conditions under which Dupuit believed the State should manage the railroads instead of offering concessions to private companies.