This article describes the construction and content of an atlas of local jurisdictions of Ancien Régime France: bailliages. Bailliages were at the center of the Ancien Régime's jurisdictional apparatus: they administered the ordinary royal justice, delineated the area of influence of heterogeneous customary laws, and served as electoral constituencies for the Estates General of 1614 and 1789. Yet, their territorial extent was relatively unknown to the royal authority, leading early scholars to assert the impossibility of mapping the geography of bailliages. Based on Armand Brette's Atlas des bailliages et juridictions assimilées published in 1904, we develop a historical geographic information system containing shapefiles and associated data files of bailliage courts at the time of the convocation of the Estates General of 1789. This new source has many potential applications, including mapping the different legal systems that coexisted in France, such as Roman law in pays de droit écrit and customary law in pays de droit coutumier, and studying elections to the Estates General of 1789.