At the turn of the twentieth century, the United States proclaimed an Open Door Policy that sought to protect China’s territorial integrity and governmental sovereignty amid fears that inter-imperial scrambles for territory would implode global capitalism. Why would the US proclaim an anti-imperial policy at a time when its settler colonial empire spread deeper into the Western Hemisphere and into the Pacific world? This project proposes that the premise of defending China’s territorial sovereignty articulated a new geopolitical strategy that sought progressive modernization and developmental aid without “formal” colonization. Amid uneven treaties that ceded land to foreign powers and various domestic frontier disputes, China’s very territory and government needed to be remade and US corporations and policymakers staked a share in this future. Rather than begin with the established borders, I digitize the construction of territorial sovereignty of China through significant agricultural, exploratory, pedagogical, and journalistic projects from the declaration of the Open Door in 1899 to the establishment of a territorially bounded communist state in 1949. This project draws upon digital humanities techniques to create an interactive map to show that the division of the world into nation-states was not merely the work of diplomats and statesmen, but required a variety of actors such as explorers, journalists, and researchers. Ultimately, I show how territorial sovereignty needed to be built anew through the collaboration between a progressive US imperialism and Chinese nationalism as geopolitics is not merely diplomatic relations but the political and material creation of new geographies.