Based on an understanding of the category of teamwork as a socio-historical construct, this chapter reconstructs four phases of its development and the driving forces behind it. The first phase was the emergence of the group-work concept in the Human Relations school as a response to the Taylorist revolution and its Scientific Management at the beginning of the twentieth century. The second phase was the institutionalization of group-work research as an important field of organizational psychology and labor sociology, with the discussion culminating in the potential of group work in the Humanization of Work programs of the 1960s and 1970s. The third phase was characterized by a changing political and economic environment in the 1980s. In this context, lean-production concepts gained in importance. They brought not only a linguistic shift from group work to teamwork but also a recombination of Taylorism and teamwork concepts. In the course of the 1990s and 2000s, the debates increasingly shifted from manufacturing sectors to the software industry and white-collar work in general. Influenced by lean concepts, the software industry became the birthplace of agile teamwork concepts. The chapter ends with a reflection on the relationship between “real-world” changes and evolution of the category of teamwork.