New research suggests literacy played an underappreciated role in state-society interactions during French nation-building. Examining marriage regulations across nineteenth-century France, the authors find strong evidence that increased literacy levels reduced transaction costs of government engagement with citizens. This study demonstrates how language skills facilitated bureaucratic encounters and enabled broader public participation in governance systems. The findings offer novel insights into political development by showing that enhancing communication capabilities helped bridge the gap between state institutions and ordinary people during a critical period of modernization.