The Schneider company, founded in 1836 by Eugène and Alphonse Schneider, is used in this paper to suggest answers to a double scientific issue: first, the close links between industrial development and military activity, and second, the individual’s decision-making rationale linked to the concept of social capital. Railways were Schneider’s first main activity. After the French defeat of 1870, Schneider invented and manufactured the "victory" 75 cannon, which saw national and international success. While the Schneiders belonged to the middle class, they owe their success largely to a network of connections with the State. The concept of social capital, which consists of knowledge capital, financial capital and connection capital, shows the importance of connection capital in explaining the ability to mobilize financial capital. The family participates extensively in the process by being the matrix behind the socialization of individuals and by contributing both knowledge and capital.