This dissertation focuses on the historian Jin Yufu (1887-1962) to examine the broader transcultural practice of writing ethno-racial histories in twentieth century Northeast Asia. An archaeologist, collector, compiler and historian of Northeast Asian history, a civil official under the Zhang Xueliang regime in Manchuria, and the assistant director of the Fengtian Library under the Manchukuo government (1932-36), Jin was closely tied to an entire network of prominent individuals in political and intellectual circles including eminent Japanese archaeologists and historians of the region. Considering his personal experiences and seminal role in shaping the narrative of Chinese national history, Jin is a key figure in understanding the development of ethnoracial historiography in twentieth century Northeast Asia. I argue that national histories in Northeast Asia developed out of transcultural processes of socio-intellectual interaction. I develop this thesis in two ways. First, I analyze the role of railways in reshaping the regional economy, enabling new forms of mobility and interaction, that simultaneously encouraged the growth of archaeological research and Jin Yufu's participation in a major Japanese excavation of the ancient ruins of the Bohai state capital in present-day Heilongjiang province. Secondly, I place Jin Yufu's classic history of Northeast China, the Dongbei Tongshi (General History of the Northeast), in context with Inaba Iwakichi's seminal 1915 work, Developmental History of Manchuria, and consider how multiple efforts to translate that work into Chinese throughout the 1930s, influenced by Jin's participation and encouragement, culminated in his classic work on Northeast China by 1941.