The Insular Cases are a set of early twentieth‐century US Supreme Court cases establishing the legal relationship between the United States and its territorial acquisitions. The Insular Cases have received limited scholarly attention in geography, despite their integral role in continuing to deny full constitutional protections to over 3.5 million American citizens and nationals. Informed by conceptualisations of territory as both process and political technology, political geography offers a critical lens through which to interpret the spatial implications of the Insular Cases. This article conducts a discourse analysis of the Insular Cases, tracing the US Supreme Court's creation of incorporated and unincorporated territorial statuses as they are positioned within contemporaneous racist logic and international norms. I argue that, by inventing differentiated categories of territory, the Insular Cases sought to spatially accommodate white supremacist imaginaries. This paper advances political geography by centring the judicial production of American territorial categories, and adds a geographic perspective to existing literature that interrogates the white supremacist, imperialist source of territorial status today.