The article examines the main trends in the socio-economic development of Northern Kazakhstan in the 19th–20th centuries. The purpose of the study is to provide a comprehensive analysis of the processes of economic modernization, migration, and changes in the ethnosocial structure of the region over two centuries. The research tasks include identifying the key stages in the transition from a traditional nomadic lifestyle to sedentary agriculture, analyzing the role of resettlement movements and agrarian reforms, and assessing the impact of industrialization and Soviet policy on the social structure. The relevance of the work is determined by the need for a systematic understanding of the region’s historical experience in the context of modern economic and ethnodemographic challenges, as well as the importance of using this knowledge for forecasting future development. A review of recent research allows us to look at these trends in the context of modern scientific discussions, considering the achievements of Russian and foreign historiography, archival sources, and the latest approaches to source analysis. The results highlight the transformation of the economic system, significant changes in demographic and ethnic composition, the formation of a regional agro-industrial center, and the consequences of modernization for the social and economic life of Northern Kazakhstan.