Patents have long been an obvious and important source for documenting technological change. In recent years, however, several studies have proposed to focus on patents as documents, by following specifications through the processes of writing, examination, courtroom argumentation and dissemination of technical information. In doing so, these studies have highlighted the role of the “technologies of the law” in the emergence and evolution of legal norms in the IP domain. The presentation will discuss the possible interaction between these strands of research, by discussing a digital history project that relies on a very large corpus of specifications—covering all patents issued in the United States between 1836 and the beginning of the twentieth century. Such an endeavour implies a careful compilation and criticism of its sources, relying both on the available specifications and other primary sources from the Patent Office. This source criticism is more than a methodological prerequisite but involves an actual investigation of the bureaucratic history of patent systems. I will focus on two themes of importance to the overall project: first, the publication of patents in the United States—on which our corpus is based; second, the introduction and evolution of technological classifications of patents, from nineteenth-century historical categories to the current constant reclassification by the Patent Office—on which many analyses tend to rely unquestioningly. The presentation will conclude by showing preliminary research results made possible by such a combination of the history of the daily administrative handling of patent documents and of the textual analysis of a very large corpus of specifications. Thus, our ongoing research opens up interesting opportunities for both the history of technological change and the workings of IP over time, furthering the “technologies of the law” literature.