Transaction records involving U.S. patent documents have been maintained by the United States Patent and Trademark Office (USPTO) for over 40 years, but have not been extensively used by scholars. One explanation is that these data have not been in a form amenable for research. To help remedy this deficiency and to foster scholarship, the USPTO Office of Chief Economist is curating internal agency records to release a series of datasets in research‐ready formats. This article describes the USPTO Patent Assignment Dataset (UPAD), a relational database of roughly 6 million assignments, licenses, securitizations, and other conveyances involving about 10 million U.S. patents and patent applications, recorded 1970–2014. To promote research uses, this article provides a comprehensive data description and presents stylized facts derived from the records. Although this article discusses several limitations inherent in using these data, the release of the UPAD creates opportunities to conduct original research, particularly relating to intellectual property collateralization and the markets for technology and innovation.