This paper examines how partisan sorting during the era of Prohibition influenced geographic representation gaps in Congress.

Introduction: The US prohibition movement provides a unique historical case to analyze dyadic representation—how members represent others outside their own districts or states. By analyzing voting patterns and roll call data from this period, we can understand whether party alignment with geography creates lasting disparities.

Data & Methods: Drawing on congressional voting records (1920-1930) linked to state-level prohibition policies, the study employs quantitative text analysis and regression models to track representation shifts across geographical divides. The dataset includes roll call votes from the US House of Representatives during a transformative period in American politics.

Key Findings: Our results reveal that partisan sorting mechanisms exacerbated geographic divisions in representing minority preferences. While urban areas increasingly aligned with prohibitionist parties, rural regions maintained their traditional stance, creating stark contrasts between the North and South regarding representation of these differing views.

Why It Matters: This historical analysis demonstrates how institutional structures interacted with social cleavages to shape dyadic representation patterns across US regional divides—a dynamic potentially relevant for understanding contemporary political representation issues. The findings suggest enduring links between geography, policy preferences, and partisan sorting effects.