This research project examines the partition of India as a natural experiment and the impact of changes in market access. For this analysis, we construct historical database and maps of British India. From the theoretical predictions of New Economic Geography, border regions would suffer substantial decline due to the decrease in market access. It is the objective of this research to test this prediction. Through the study of historical economic division, which is the opposite of economic integration, we intend to contribute to the understandings of future economic integration in South Asia.