Research on the “new second generation” takes the success of the earlier second generation of southern and eastern Europeans as its point of departure, but with little empirical basis. The hypothesis of “segmented assimilation” asserts that the children of the 1880–1920 immigration moved ahead due to the availability of well-paying, relatively low-skilled jobs in manufacturing. By contrast, defenders of the conventional approach to assimilation accent diffusionary processes, while conceding that the specific means by which the children of immigrants improved on their parents’ condition remains a matter about which relatively little is known. This article returns to the world of the last second generation, just before it disappeared, to inquire into the extent and nature of the economic differences separating the adult immigrant offspring of the time from their third-generation-plus counterparts. Using data from the 1970 Census of Population, this article shows that manufacturing mattered, but in ways neither expected nor consistent with either of today's prevailing, theoretical approaches.