After encountering the initial glimpses of gradation in the first assembly, this chapter explores a second moment in the developments of New York City’s school system. The section follows the assembly process between 1898 and 1921 that enabled the institutionalization of age-grading. The study delineates the specific characteristics of the translation process for each of the featured actors. Compared to the first assembly, the gradation network presents itself as a more complex, multi-branched constellation with actors assuming new or different roles. At the same time, some actors from the first network reappear in this constellation, albeit in modified form. The chapter closes with a discussion about the developments that occurred between the networks and which elements were decisive in establishing the age-graded classroom.