This article introduces the Knappschaft statistics as a basic source for quantitative data on a very important topic in historical social research, namely the rise of the welfare state. Scholars who seek to embark upon historical social research in that direction require both qualitative and quantitative data. Exploring data sources and making data available for general use thus is crucial to systematic research and scholarly discourse. For the period 1861 to 1920, the Knappschaft statistics document the operation of the various German Knappschaftsvereine as the carriers of miners’ occupational social insurance at the time. Data on the various Knappschaften are quite rich enabling us to use them as a “historical laboratory” not merely to study the welfare positions of and social relations in a particular societal class in a particular period, but to explore more general questions related to the roots of modern welfare states, their functioning, and the challenges they face. To stress this point, I combine the concise overview of the Knappschaft statistics with a straightforward application to the question of the consequences of aging in a pay-as-you-go pension system.