Mapping the State leads to a fundamental rethinking of the 1832 Reform Act by demonstrating how boundary reform underpinned this turning point in the development of the British political nation. Using significant new archival discovery, digital methods and ’big data’, it provides a major reassessment of why and how the 1832 Reform Act passed, its impact on reformed politics both at Westminster and in the constituencies, and its significance to the expansion of the modern British state.